Photosensitive polyimide compositions

ABSTRACT

This disclosure relates to a dry film structure that includes a carrier substrate, and a polymeric layer supported by the carrier substrate. The polymeric layer includes at least one fully imidized polyimide polymer.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application claims priority to U.S. Provisional ApplicationSer. No. 62/263,372, filed on Dec. 4, 2015, U.S. Provisional ApplicationSer. No. 62/185,424, filed on Jun. 26, 2015, U.S. ProvisionalApplication Ser. No. 62/150,381, filed on Apr. 21, 2015. The priorapplications are hereby incorporated by reference in their entirety.

BACKGROUND OF THE DISCLOSURE

Increasingly, semiconductor devices are being utilized in many newembedded applications including a host of new mobile devices. In orderto allow this expansion to continue, the manufacturing costs for thesesemiconductor devices must be reduced. While multiple pathways are beingpursued, switching from wafers to large non-circular panels offersseveral key cost advantages.

Circular substrates, such as silicon wafers, permit coating materialslike photoresists and dielectric materials to be applied by spincoating. For decades, spin coating has been the preferred method forapplying photosensitive materials to semiconductor substrates. In recentyears the semiconductor industry has begun to explore methods forapplying photosensitive coatings to large, non-circular panelsubstrates. These substrates, which may be flexible or rigid, presentspecial challenges and require alternative methods for processing andapplying semiconductor coatings. One preferred method for applyingcoatings to these advanced substrates is the use of a dry, polymericfilm which can be applied to virtually any type of substrate. Onceapplied, the dry film is then laminated so that the semiconductorcoating is affixed to the substrate. In the case of a photoimageable dryfilm resist material, after this lamination step the resist material ispatternwise exposed to radiation and developed.

One important class of photoimageable dry film resist materials isphotoimageable dielectrics (PIDs). Next generation semiconductorpackaging requires PID materials that possess a combination of excellentlithographic resolution, superior thermal and mechanical properties aswell as chemical stability. Resolution of these PID materials shouldallow the printing of fine features (<3 microns) with high aspect ratios(>2:1). Current PID materials possess numerous deficiencies making themunable to meet the requirements of next generation semiconductorpackaging applications. Two key obstacles that current materials haveyet to overcome are (1) patterning of high resolution (<3 micron)features and (2) production of thin (<5 micron) PID dry films. Thisnecessitates the development of advanced dry film PID materials to meetthese needs. The dry film PID materials of this disclosure address theneeds of advanced packaging applications by overcoming the limitationsof current materials.

SUMMARY OF THE DISCLOSURE

In one aspect, this disclosure features a dry film structure thatincludes a carrier substrate, and a photosensitive polymeric layersupported by the carrier substrate, the photosensitive polymeric layerincluding at least one fully imidized polyimide polymer; wherein thephotosensitive polymeric layer has a film thickness of at most about 5microns (e.g., at most about 4 microns or at most about 3 microns). Insome embodiments, the photosensitive polymeric layer further includes atleast one reactive functional compound (RFC) and at least onephotoinitiator.

In some embodiment the at least one fully imidized polyimide polymer isprepared from at least one diamine, the at least one diamine including acompound selected from the group consisting of a diamine of Structure(Ia) and a diamine of Structure (Ib),

in which each of R¹, R², R³, R⁴, R⁵, R¹¹, R¹², R¹³, and R¹⁴,independently, is H, a substituted or unsubstituted C₁-C₆ linear orbranched alkyl group, or a C₅-C₇ cycloalkyl group.

In some embodiments, the at least one diamine is selected from the groupconsisting of 1-(4-aminophenyl)-1,3,3-trimethylindan-5-amine,1-(4-aminophenyl)-1,3,3-trimethyl-2H-inden-5-amine,1-(4-aminophenyl)-1,3,3-trimethyl-indan-5-amine,[1-(4-aminophenyl)-1,3,3-trimethyl-indan-5-yl]amine, and1-(4-aminophenyl)-2,3-dihydro-1,3,3-trimethyl-1H-inden-5-amine),5-amino-6-methyl-1-(3′-amino-4′-methylphenyl)-1,3,3-trimethylindan,4-amino-6-methyl-1-(3′-amino-4′-methylphenyl)-1,3,3-trimethylindan,5,7-diamino-1,1-dimethylindan, 4,7-diamino-1,1-dimethylindan,5,7-diamino-1,1,4-trimethylindan, 5,7-diamino-1,1,6-trimethylindan, and5,7-diamino-1,1-dimethyl-4-ethylindan.

In some embodiments, the at least one diamine includes (a) a compoundselected from the group consisting of a diamine of Structure (Ia) and adiamine of Structure (Ib), and (b) at least one diamine of Structure(II),

in which R¹⁵, R¹⁶, R¹⁷ and R¹⁸, independently, can be H, a substitutedor unsubstituted C₁-C₆ linear or branched alkyl group, or C₅-C₇cycloalkyl group, provided that at least two of R¹⁵, R¹⁶, R¹⁷ and R¹⁸are not hydrogen.

In some embodiments, the at least one diamine of Structure (II) isselected from the group consisting of2,3,5,6-tetramethylphenylenediamine, 2,4-diamino-1,3,5-trimethylbenzene,2,4-diamino-1,3,5-triethylbenzene,2,4-diamino-3,5-dimethyl-1-ethylbenzene,2,4-diamino-1,5-dimethyl-3-ethylbenzene2,4-diamino-1,3,5-triisopropylbenzene,2,3,5,6-tetraisopropyl-phenylenediamine and2,4-diamino-1,3,5,6-tetramethylbenzene.

In some embodiments, the at least one fully imidized polyimide polymeris prepared from at least one dianhydride, the at least one dianhydrideincluding a compound selected from the group consisting of3,3′,4,4′-benzophenone tetracarboxylic dianhydride,3,3′,4,4′-diphenylsulfone tetracarboxylic dianhydride,3,3′,4,4′-diphenyl ether tetracarboxylic dianhydride, 2,3,3′,4′-diphenylether tetracarboxylic dianhydride, and 2,2-[bis(3, 4-dicarboxyphenyl)]hexafluoropropane dianhydride.

In some embodiments, the at least one fully imidized polyimide polymeris prepared from at least one dianhydride, the at least one dianhydrideincluding a compound selected from the group consisting of:

In some embodiments, the reactive functional compound includes at leastone functional group selected from the group consisting of a vinylgroup, an allyl group, a vinyl ether group, a propenyl ether group, a(meth)acryloyl group, an a SiH group, and a thiol group.

In some embodiments, the reactive functional compounds is selected fromthe group consisting of 1,6-hexanediol di(meth)acrylate,tetraethyleneglycol di(meth)acrylate, divinylbenzene, ethoxylatedbisphenol-A-di(meth)acrylate, diethylene glycol bis(allyl carbonate),trimethylolpropane tri(meth)acrylate, ditrimethylolpropanetetra(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritoltetra(meth)acrylate, dipentaerythritol penta-/hexa-(meth)acrylate,isocyanurate tri(meth)acrylate, bis(2-hydroxyethyl)-isocyanuratedi(meth)acrylate, 1,3-butanediol tri(meth)acrylate, 1,4-butanedioltri(meth)acrylate, methyl (meth)acrylate, butyl (meth)acrylate,cyclohexyl (meth)acrylate, benzyl(meth)acrylate, neopentyl glycoldi(meth)acrylate, (meth)acrylate modified-urea-formaldehyde resins,(meth)acrylate modified melamine-formaldehyde resins and (meth)acrylatemodified cellulose.

In some embodiments, the dry film structure can further include aprotective layer, in which the first polymeric layer is between thecarrier substrate and the protective layer.

In some embodiments, the dry film structure can further include a secondpolymeric layer, in which the second polymeric layer is between thephotosensitive polymeric layer and the carrier substrate or the secondpolymeric layer is between the photosensitive polymeric layer and theoptional protective layer. In some embodiments, the second polymericlayer can include a water soluble polymer.

In some embodiments, the photosensitive polymeric layer is capable offorming a patterned layer containing at least one element having afeature size of at most about 3 microns after the photosensitivepolymeric layer is exposed to actinic radiation and developed.

In some embodiments, this disclosure features methods for preparation ofa dry film structure. The method includes: (a) coating a carriersubstrate with a photosensitive polymeric composition (e.g., a negativetone photosensitive polymeric composition) to form a coated composition,(b) drying the coated composition to form a photosensitive polymericlayer, and (c) applying a protective layer to the photosensitivepolymeric layer to form a dry film structure. In some embodiments, thephotosensitive polymeric layer has a film thickness of at most about 5microns. In some embodiments, the photosensitive polymeric compositioncontains at least one polyimide polymer described in this disclosure, atleast one reactive functional compound (RFC), at least one initiator,and optionally at least one solvent.

In some embodiments, this disclosure features a process of forming alaminate. The process can include applying the dry film structuredescribed herein onto an electronic substrate to form a laminate. Inembodiments where the dry film structure includes a protective layer,the process can further include removing the protective layer from thedry film structure before applying the dry film structure. In someembodiments, the process can further include converting thephotosensitive polymeric layer into a patterned layer. The conversioncan include exposing the photosensitive polymeric layer in the laminateto actinic radiation. In such embodiments, the conversion can furtherinclude removing the carrier substrate before or after exposing thephotosensitive polymeric layer. After the photosensitive polymeric layeris exposed to actinic radiation, the conversion can further includedeveloping the exposed photosensitive polymeric layer to form apatterned layer having a relief pattern. The developing can includeremoving unexposed portions in the polymeric layer by using a developerto form a patterned layer having a relief pattern and rinsing the reliefpattern on the substrate with a solvent or a mixture of solvents.

In some embodiments, this disclosure features a process of forming apatterned film (e.g., a laminate containing a patterned film). Such aprocess can be performed, for example, by: (a) providing a dry filmstructure including: a carrier substrate; a protective layer; and aphotosensitive polymeric layer between the carrier substrate and theprotective layer; in which the photosensitive polymeric layer has a filmthickness of at most about 5 microns, (b) removing the protective layerfrom the dry film structure; (c) applying the structure obtained in step(b) onto an electronic substrate to form a laminate, the laminatecontaining the photosensitive polymeric layer between the electronicsubstrate and the carrier substrate; and (d) converting thephotosensitive polymeric layer into a patterned layer; in which thepatterned layer has a thickness of at most about 5 microns (e.g., atmost about 4 microns or at most about 3 microns) and includes at leastone element having a feature size of at most about 3 microns. In someembodiments, the photosensitive polymeric layer include at least onefully imidized polyimide polymer; at least one reactive functionalcompound (RFC), and at least one photoinitiator.

In some embodiments, this disclosure features a three dimensional objectincluding at least one pattern film formed by a process describedherein. In some embodiments, the three dimensional objects can includepattern films in at least two stacks (e.g., at least three stacks).

In some embodiments, the disclosure features a semiconductor device thatincludes the three dimensional object described herein. In someembodiments, the semiconductor device is an integrated circuit, a lightemitting diode, a solar cell, or a transistor.

DETAILED DESCRIPTION OF THE DISCLOSURE

In the context of this disclosure, lamination is a process for affixingor adhering the polymeric layer of a dry film structure to a surface ofa substrate (e.g., an electronic substrate). Pre-lamination is treatmentof the substrate prior to lamination. Pre-lamination includes, but isnot limited to, rinsing the substrate with solvent or additive anddrying before lamination.

As mentioned herein, the phrase “unexposed film” or “a film unexposed toactinic radiation” refers to a film unexposed to actinic radiation underlithographic conditions used to form patterns.

As used herein, the term “fully imidized” means the polyimide polymersof this disclosure are at least about 90% (e.g., at least about 95%, atleast about 98%, at least about 99%, or about 100%) imidized.Imidization to form a polyimide can be confirmed by observation ofcharacteristic absorptions in the infrared spectrum from 1770 and 1700cm⁻¹ attributable to the imide ring structure.

In general, this disclosure relates to dry film structures and laminatesformed by such a dry film structure, as well as the processes of makingor using the dry film structures or laminates. In some embodiments, thedry film structures can include a carrier substrate, and aphotosensitive polymeric layer supported by the carrier substrate. Thephotosensitive polymeric layer can be prepared from a photosensitivepolymeric composition (e.g., a negative tone photosensitive polymericcomposition) by coating the composition on a carrier substrate. Thephotosensitive polymeric layer or photosensitive polymeric compositioncan contain the following components: (A) at least one polyimide polymer(e.g., at least one fully imidized polyimide polymer), (B) at least onereactive functional compound (RFC); and (C) at least one photoinitiator.In some embodiments, the dry film structure can further include aprotective layer such that the photosensitive polymeric layer is betweenthe carrier substrate and the protective layer. In some embodiments, thephotosensitive polymeric layer can have a film thickness of at most 5microns and a resolution (e.g., the feature size of an element formed inthe photosensitive polymeric layer) of at most 3 microns.

In some embodiments, the at least one fully imidized polyimide (i.e.,component (A)) of the photosensitive polymeric composition or thepolymeric layer of the dry film structure is prepared by reaction of atleast one diamine as a monomer with at least one dianhydride (e.g., atleast one tetracarboxylic acid dianhydride) as another monomer. Examplesof diamines include, but are not limited to,1-(4-aminophenyl)-1,3,3-trimethylindan-5-amine (alternative namesincluding 4,4′-[1,4-phenylene-bis(1-methylethylidene)]bisaniline),1-(4-aminophenyl)-1,3,3-trimethyl-2H-inden-5-amine,1-(4-aminophenyl)-1,3,3-trimethyl-indan-5-amine,[1-(4-aminophenyl)-1,3,3-trimethyl-indan-5-yl]amine, and1-(4-aminophenyl)-2,3-dihydro-1,3,3-trimethyl-1H-inden-5-amine),5-amino-6-methyl-1-(3′-amino-4′-methylphenyl)-1,3,3-trimethylindan,4-amino-6-methyl-1-(3′-amino-4′-methylphenyl)-1,3,3-trimethylindan,5,7-diamino-1,1-dimethylindan, 4,7-diamino-1,1-dimethylindan,5,7-diamino-1,1,4-trimethylindan, 5,7-diamino-1,1,6-trimethylindan,5,7-diamino-1,1-dimethyl-4-ethylindan, p-phenylenediamine,m-phenylenediamine, o-phenylenediamine, 3-methyl-1,2-benzene-diamine,1,2-diaminoethane, 1,3-diaminopropane, 1,4-diaminobutane,1,5-diaminopentane, 1,6-diaminohexane, 1,7-diaminoheptane,1,8-diaminooctane, 1,9-diaminononane, 1,10-diaminodecane,1,2-diaminocyclohexane, 1,4-diaminocyclohexane,1,3-cyclohexanebis(methylamine), 5-amino-1,3,3-trimethylcyclohexanemethanamine, 2,5-diaminobenzotrifluoride,3,5-diaminobenzotrifluoride, 1,3-diamino-2,4,5,6-tetrafluorobenzene,4,4′-oxydianiline, 3,4′-oxydianiline, 3,3′-oxydianiline,3,3′-diaminodiphenylsulfone, 4,4′-diaminodiphenylsulfones,4,4′-isopropylidenedianiline, 4,4′-diaminodiphenylmethane,2,2-bis(4-aminophenyl)propane, 4,4′ diaminodiphenyl propane,4,4′-diaminodiphenyl sulfide, 4,4′-diaminodiphenylsulfone,4-aminophenyl-3-aminobenzoate, 2,2′-dimethyl-4,4′-diaminobiphenyl,3,3′-dimethyl-4,4′-diaminobiphenyl, 2,2′-bis (trifluoromethyl)benzidine, 3,3′-bis (trifluoromethyl) benzidine, 2,2-bis[4-(4-aminophenoxy phenyl)] hexafluoropropane, 2,2-bis(3-amino-4-methylphenyl)-hexafluoropropane,2,2-bis(3-aminophenyl)-1,1,1,3,3,3-hexafluoropropane,1,3-bis-(4-aminophenoxy)benzene, 1,3-bis-(3-aminophenoxy)benzene,1,4-bis-(4-aminophenoxy)benzene, 1,4-bis-(3-aminophenoxy)benzene,1-(4-aminophenoxy)-3-(3-aminophenoxy)benzene,2,2′-bis-(4-phenoxyaniline)isopropylidene,bis(p-beta-amino-t-butylphenyl)ether,p-bis-2-(2-methyl-4-aminopentyl)benzene,p-bis(1,1-dimethyl-5-aminopentyl)benzene,3,3′-dimethyl-4,4′-diaminobiphenyl, 4,4′-diaminobenzophenone,3′-dichlorobenzidine, 2,2-bis [4-(4-aminophenoxy)phenyl] propane,4,4′-[1,3-phenylenebis(1-Methyl-ethylidene)] bisaniline,4,4′-[1,4-phenylenebis(1-methyl-ethylidene)]bisaniline, 2,2-bis[4-(4-aminophenoxy) phenyl] sulfone, 2,2-bis [4-(3-aminophenoxy)benzene], 1,4-bis (4-aminophenoxy) benzene, 1,3-bis (4-aminophenoxy)benzene, (1,3′-bis (3-aminophenoxy) benzene, and9H-fluorene-2,6-diamine.

In some embodiments, the at least one diamine includes a compoundselected from the group consisting of a diamine of Structure (Ia) and adiamine of Structure (Ib):

in which each of R¹, R², R³, R⁴, R⁵, R¹¹, R¹², R¹³, and R¹⁴,independently, is H, a substituted or unsubstituted C₁-C₆ linear orbranched alkyl group, or C₅-C₇ cycloalkyl group.

Examples of the substituted or unsubstituted C₁-C₆ linear or branchedalkyl groups in R¹, R², R³, R⁴, R⁵, R¹¹, R¹², R¹³, and R¹⁴ include, butare not limited to, methyl, ethyl, propyl, isopropyl, butyl, isobutyl,t-butyl, amyl, hexyl, and 2-methylhexyl. Examples of the C₅-C₇cycloalkyl group in R¹, R², R³, R⁴, R⁵, R¹¹, R¹², R¹³, and R¹⁴ include,but are not limited to, cyclopentyl, cyclohexyl, and cycloheptyl.

Examples of diamines of Structure (Ia) or (Ib) include, but are notlimited to, 1-(4-aminophenyl)-1,3,3-trimethylindan-5-amine (alternativenames including 4,4′-[1,4-phenylene-bis(1-methylethylidene)] bisaniline,1-(4-aminophenyl)-1,3,3-trimethyl-2H-inden-5-amine, 1-(4-aminophenyl)-1,3,3-trimethyl-indan-5-amine,[1-(4-aminophenyl)-1,3,3-trimethyl-indan-5-yl]amine, and1-(4-aminophenyl)-2,3-dihydro-1,3,3-trimethyl-1H-inden-5-amine),5-amino-6-methyl-1-(3′-amino-4′-methylphenyl)-1,3,3-trimethylindan,4-amino-6-methyl-1-(3′-amino-4′-methylphenyl)-1,3,3-trimethylindan,5,7-diamino-1,1-dimethylindan, 4,7-diamino-1,1-dimethylindan,5,7-diamino-1,1,4-trimethylindan, 5,7-diamino-1,1,6-trimethylindan, and5,7-diamino-1,1-dimethyl-4-ethylindan.

In some embodiments, the at least one diamine includes (a) a compoundselected from the group consisting of a diamine of Structure (Ia) and adiamine of Structure (Ib), and (b) at least one diamine of Structure(II),

in which each of R¹⁵, R¹⁶, R¹⁷ and R¹⁸, independently, can be H, asubstituted or unsubstituted C₁-C₆ linear or branched alkyl group, orC₅-C₇ cycloalkyl group, provided that at least two of R¹⁵, R¹⁶, R¹⁷ andR¹⁸ are not hydrogen.

Examples of the substituted or unsubstituted C₁-C₆ linear or branchedalkyl groups in R¹⁵, R¹⁶, R¹⁷ and R¹⁸ include, but are not limited to,methyl, ethyl, propyl, isopropyl, butyl, isobutyl, t-butyl, amyl, hexyl,and 2-methylhexyl. Examples of the C₅-C₇ cycloalkyl group in R¹⁵, R¹⁸,R¹⁷ and R¹⁸ include, but are not limited to, cyclopentyl, cyclohexyl,and cycloheptyl.

Examples of diamines of Structure (II) include, but are not limited to,2,3,5,6-tetramethylphenylenediamine, 1,4-diamino-1,3,5-trimethylbenzene,2,4-diamino-1,3,5-triethylbenzene,2,4-diamino-3,5-dimethyl-1-ethylbenzene,2,4-diamino-1,5-dimethyl-3-ethylbenzene,2,4-diamino-1,3,5-triisopropylbenzene,2,3,5,6-tetraisopropyl-phenylenediamine and2,4-diamino-1,3,5,6-tetramethylbenzene.

In some embodiments, the molar percentage of the diamines of Structures(Ia) and (Ib) in the total amount of diamines (e.g., diamines ofStructures (Ia), (Ib), and (II)) is at least about 10% (e.g., at leastabout 20%, at least about 25%, at least about 30%, at least about 35%,at least about 40%, at least about 45%, or at least about 50%) to atmost about 90% (e.g., at most about 85%, at most about 80%, at mostabout 75%, at most about 70%, at most about 65%, or at most about 60%).

In some embodiments, the molar percentage of the diamines of Structure(II) in the total amount of diamines (e.g., diamines of Structure (Ia),(Ib), and (II)) is at least about 10% (e.g., at least about 20%, atleast about 25%, at least about 30%, at least about 35%, at least about40%, at least about 45%, or at least about 50%) to at most about 90%(e.g., at most about 85%, at most about 80%, at most about 75%, at mostabout 70%, at most about 65%, or at most about 60%).

In general, to form a polyimide polymer described herein, the diaminescan be reacted with at least one dianhydride, such as at least onetetracarboxylic acid dianhydride.

In some embodiments, the tetracarboxylic acid dianhydrides have theStructure (V) with a moiety Y.

In formula (V), the moiety Y is a tetravalent organic group, such as agroup selected from the group consisting of:

-   -   a) a substituted or unsubstituted C₆-C₁₈ mononuclear or fused        polynuclear aromatic group,    -   b) a substituted or unsubstituted C₂-C₁₈ linear, branched,        cyclic or fused polycyclic alkylene group,    -   c) a substituted or unsubstituted heterocyclic group,    -   d) a tetravalent group of Structure (VI-a), (VI-b), (VI-c),        (VI-d), (VI-e), (VI-f), (VI-g), (VI-h), (VI-i), or (VI-j), where        R³¹ to R⁴¹ are independently a hydrogen atom or a substituted or        unsubstituted C₁-C₁₀ linear or branched alkyl group (e.g., a        partially or fully halogen substituted C₁-C₁₀ alkyl group) and        L³ to L⁶ are independently selected from the group consisting of        an unsubstituted or substituted carbon atom, an oxygen atom, a        sulfur atom, a —(C═O)— group, a —[S(═O)₂]— group and a —(S═O)—        group,

-   -   e) a tetravalent group [D¹-L¹-D²] where, D¹ and D² are        independently selected from the group consisting of:        -   1. a substituted or unsubstituted C₅-C₁₈ monocyclic or            polycyclic aliphatic group, and        -   2. a substituted or unsubstituted C₆-C₁₈ mononuclear or            polynuclear aromatic group,    -   and L¹ is a divalent linking group selected from the group        consisting of:        -   1. a single bond,        -   2. a substituted or unsubstituted C₁-C₂₀ linear, branched,            monocyclic or polycyclic alkylene group,        -   3. a substituted or unsubstituted C₂ alkenylene group,        -   4. a C₂ alkynylene group,        -   5. a substituted or unsubstituted C₆-C₁₈ mononuclear or            fused polynuclear aromatic group,        -   6. an oxygen atom,        -   7. a sulfur atom,        -   8. a —(C═O)— group,        -   9. a —[S(═O)₂]—0 group,        -   10. a —(S═O)— group,        -   11. a —[C(═O)O]— group,        -   12. a —[C(═O)NH]— group, and        -   13. a —[O(C(R⁶¹)₂(CR⁶²)₂O)_(n3)]— group, where n3 ranges            from 1 to about 6 and R⁶¹ and R⁶² are independently a            hydrogen atom or a substituted or unsubstituted C₁-C₆            linear, or branched alkyl group (e.g., a partially or fully            halogen substituted C₁-C₆ alkyl group).

Examples of divalent linking groups L¹ include, but are not limited to,those shown below of which each of n3, n4 and n5, independently, has thesame meaning defined above:

Suitable examples of Y include, but are not limited to, the followingmoieties:

Examples of the tetracarboxylic acid anhydrides include, but are notlimited to,1-(3′,4′-dicarboxyphenyl)-1,3,3-trimethylindan-5,6-dicarboxylic aciddianhydride,1-(3′,4′-dicarboxyphenyl)-1,3,3-trimethylindan-6,7-dicarboxylic aciddianhydride, 1-(3′,4′-dicarboxyphenyl)-3-methylindan-5,6-dicarboxylicacid dianhydride, and1-(3′,4′-dicarboxyphenyl)-3-methylindan-6,7-dicarboxylic acid anhydride,pyromellitic dianhydride, benzene-1,2,3,4-tetracarboxylic dianhydride,2,3,5,6-naphthalenetetracarboxylic acid dianhydride,2,3,6,7-naphthalenetetracarboxylic acid dianhydride,1,4,5,8-naphthalenetetracarboxylic acid dianhydride,2,6-dichloronaphthalene-1,4,5,8-tetracarboxylic dianhydride,2,7-dichloronaphthalene-1,4,5,8-tetracarboxylic dianhydride,2,3,6,7-tetrachloronaphthalene-1,4,5,8-tetracarboxylic dianhydride,phenanthrene-,8,9,10-tetracarboxylic dianhydride,3,4,9,10-perylenetetracarboxylic acid dianhydride,pyrazine-2,3,5,6-tetracarboxylic dianhydride,thiophene-2,3,4,5-tetracarboxylic dianhydride,2,3,5,6-pyridinetetracarboxylic acid dianhydride,butane-1,2,3,4-tetracarboxylic acid dianhydride,1,2,3,4-cyclopentanetetracarboxylic acid dianhydride,cyclobutane-1,2,3,4-tetracarboxylic acid dianhydride,cyclopentane-1,2,3,4-tetracarboxylic acid dianhydride,cyclohexane-1,2,4,5-tetracarboxylic acid dianhydride,norbornane-2,3,5,6-tetracarboxylic acid dianhydride,bicyclo[2.2.2]oct-7-ene-3,4,8,9-tetracarboxylic acid dianhydride,tetracyclo[4.4.1.0^(2,5).0^(7,10)]undecane-1,2,3,4-tetracarboxylic aciddianhydride, 3,3′,4,4′-benzophenone tetracarboxylic dianhydride,2,2′,3,3′-benzophenone tetracarboxylic dianhydride,2,3,3′,4′-benzophenone tetracarboxylic dianhydride,3,3′,4,4′-diphenylsulfone tetracarboxylic dianhydride,2,2′,3,3′-diphenylsulfone tetracarboxylic dianhydride,2,3,3′,4′-diphenylsulfone tetracarboxylic dianhydride,3,3′,4,4′-diphenyl ether tetracarboxylic dianhydride, 2,2′,3,3′-diphenylether tetracarboxylic dianhydride, 2,3,3′,4′-diphenyl ethertetracarboxylic dianhydride, 2,2-[bis(3, 4-dicarboxyphenyl)]hexafluoropropane dianhydride, ethyleneglycol bis(anhydrotrimellitate),and 5-(2,5-dioxotetrahydro)-3-methyl-3-cyclohexene-1,2-dicarboxylicanhydride.

Examples of preferred tetracarboxylic acid dianhydride monomers include,but are not limited to,1-(3′,4′-dicarboxyphenyl)-1,3,3-trimethylindan-5,6-dicarboxylic aciddianhydride,1-(3′,4′-dicarboxyphenyl)-1,3,3-trimethylindan-6,7-dicarboxylic aciddianhydride, 1-(3′,4′-dicarboxyphenyl)-3-methylindan-5,6-dicarboxylicacid dianhydride, and1-(3′,4′-dicarboxyphenyl)-3-methylindan-6,7-dicarboxylic acid anhydride,pyrazine-2,3,5,6-tetracarboxylic dianhydride,thiophene-2,3,4,5-tetracarboxylic dianhydride,2,3,5,6-pyridinetetracarboxylic acid dianhydride,norbornane-2,3,5,6-tetracarboxylic acid dianhydride,bicyclo[2.2.2]oct-7-ene-3,4,8,9-tetracarboxylic acid dianhydride,tetracyclo[4.4.1.0^(2.5).0^(7,10)]undecane-1,2,3,4-tetracarboxylic aciddianhydride, 3,3′,4,4′-benzophenone tetracarboxylic dianhydride,3,3′,4,4′-diphenylsulfone tetracarboxylic dianhydride,3,3′,4,4′-diphenyl ether tetracarboxylic dianhydride, 2,3,3′,4′-diphenylether tetracarboxylic dianhydride, 2,2-[bis(3,4-dicarboxyphenyl)]hexafluoropropane dianhydride, ethyleneglycol bis(anhydrotrimellitate),and 5-(2,5-dioxotetrahydro)-3-methyl-3-cyclohexene-1,2-dicarboxylicanhydride. More preferred tetracarboxylic acid dianhydride monomersinclude 3,3′,4,4′-benzophenone tetracarboxylic dianhydride,3,3′,4,4′-diphenylsulfone tetracarboxylic dianhydride,3,3′,4,4′-diphenyl ether tetracarboxylic dianhydride, 2,3,3′,4′-diphenylether tetracarboxylic dianhydride, and 2,2-[bis(3,4-dicarboxyphenyl)]hexafluoropropane dianhydride. Any suitable combination oftetracarboxylic acid dianhydride monomers described above in anysuitable ratio can be used to form the polyimide polymer describeherein.

In some embodiments, examples of tetracarboxylic acid dianhydridemonomers include:

In some embodiments, the at least one diamine is selected from the groupconsisting of a diamine of Structure (Ia) and a diamine of Structure(Ib), and the tetracarboxylic acid dianhydride is selected from thegroup consisting of pyrazine-2,3,5,6-tetracarboxylic dianhydride,thiophene-2,3,4,5-tetracarboxylic dianhydride,2,3,5,6-pyridinetetracarboxylic acid dianhydride,norbornane-2,3,5,6-tetracarboxylic acid dianhydride,bicyclo[2.2.2]oct-7-ene-3,4,8,9-tetracarboxylic acid dianhydride,tetracyclo[4.4.1.0^(2,5).0^(7,10)]undecane-1,2,3,4-tetracarboxylic aciddianhydride, 3,3′,4,4′-benzophenone tetracarboxylic dianhydride,3,3′,4,4′-diphenylsulfone tetracarboxylic dianhydride,3,3′,4,4′-diphenyl ether tetracarboxylic dianhydride, 2,3,3′,4′-diphenylether tetracarboxylic dianhydride, 2,2-[bis(3,4-dicarboxyphenyl)]hexafluoropropane dianhydride, ethyleneglycol bis(anhydrotrimellitate),and 5-(2,5-dioxotetrahydro)-3-methyl-3-cyclohexene-1,2-dicarboxylicanhydride.

In some embodiments, the at least one diamine is selected from the groupconsisting of a diamine of Structure (Ia) and a diamine of Structure(Ib), and the tetracarboxylic acid dianhydride is selected from a groupconsisting of 3,3′,4,4′-benzophenone tetracarboxylic dianhydride,3,3′,4,4′-diphenylsulfone tetracarboxylic dianhydride,3,3′,4,4′-diphenyl ether tetracarboxylic dianhydride, 2,3,3′,4′-diphenylether tetracarboxylic dianhydride, and 2,2-[bis(3,4-dicarboxyphenyl)]hexafluoropropane dianhydride.

In some embodiments, the at least one diamine is reacted with at leastone tetracarboxylic acid dianhydride to yield a polyamic acid ofStructure (VII), where a is an integer ranging from at least 2 (e.g., atleast 3, at least 4, at least 5, at least 6, at least 8, at least 10, orat least 15) to at most 500 (e.g., at most 450, at most 400, at most350, at most 300, at most 250, at most 200, at most 150, at most 100, orat most 50), X is the nucleus of the precursor diamine, and Y is thenucleus of the precursor dianhydride and is defined above. As usedherein, when referring to the precursor diamine, “nucleus” refers to theportion of the molecule between the amine functional groups. Whenreferring to the precursor dianhydride, “nucleus” refers to the portionof the molecule between the anhydride functional groups.

The polyamic acid of Structure (VII) can be synthesized by numeroussynthetic procedures or variations of those procedures known to thoseskilled in the art. In general, a polyamic acid of Structure (VII) canbe formed through a condensation polymerization reaction between one ormore diamines and one or more tetracarboxylic acid dianhydrides. Forexample, one can bring one or more diamines in contact with one or moretetracarboxylic acid dianhydrides in the presence of a solvent suitableto dissolve the monomers and, preferably, the resultant polyamic acid.

In some embodiments, to prepare a polyamic acid, the diamine componentand tetracarboxylic acid dianhydride component are charged into areaction vessel at the same time or by charging one of the components inthe form of a solid or solution into a solution of the other component(complete dissolution of all materials might not occur). In someembodiments, charging both components at the same time can beadvantageous in view of the productivity because the time required forcharging is shortened. Generally, the condensation polymerizationreaction between the diamine component and tetracarboxylic aciddianhydride component can be carried out at about 15° C. to about 80° C.for about 1 to about 48 hours.

Suitable polymerization solvents useful in the present disclosureinclude, but are not limited to, N-methyl-2-pyrrolidone,N,N-dimethylformamide, dimethylsulfoxide, gamma -butyrolactone,N,N-dimethylacetamide, tetramethylene sulfone, p-chlorophenol, m-cresol,diethyleneglycol methyl ether, methyl-3-methoxyproprionate,ethyl-3-ethoxypropionate, cyclohexanone, propylene glycol monomethylether acetate, and 2-chloro-4-hydroxytoluene. These solvents can be usedsingly or in combination of two or more. Of these solvents, preferredare N-methyl-2-pyrrolidone, gamma-butyrolactone andN,N-dimethylacetamide, with N-methyl-2-pyrrolidone being more preferred.In some embodiments, a poor solvent for the polyimide can be used incombination with these solvents in such an amount to not allow thepolyamic acid to precipitate. Examples of such a poor solvent includehexane, heptane, benzene, toluene, xylene, chlorobenzene ando-dichlorobenzene. The amount of the poor solvent to be used ispreferably 50 percent by weight or less (inclusive of zero) based on thetotal amount of the solvents. The polyamic acid thus produced can beisolated by precipitation into a non-solvent or a poor solvent andcollected by filtration, followed by further synthetic processes forconversion to a polyimide. In some embodiments, such isolation of thepolyamic acid is not required.

In some embodiments, the molar ratio of diamine component(s) totetracarboxylic acid dianhydride component(s) can be greater than 1.00.The resulting polymer is an amino-terminated polyamic acid (e.g., apolyamic acid of Structure (VIIa)). The molar ratio of diaminecomponent(s) to tetracarboxylic acid dianhydride component(s) can rangefrom 1.01 to 1.40 and can have a direct effect on final molecular weightof polyamic acid and polyimide prepared by imidization of the polyamicacid. In some embodiments, the molar ratio is selected such that thepolyamic acid at the end of reaction has a weight average molecularweight (Mw) of at least about 10,000 Daltons (e.g. at least about 20,000Daltons, at least about 30,000 Daltons, at least about 40,000 Daltons,or at least about 50,000 Daltons) and/or at most about 90,000 Daltons(e.g. at most about 80,000 Daltons, at most about 70,000 Daltons, atmost about 60,000 Daltons).

When a molar excess of tetracarboxylic acid dianhydride is employed, ananhydride-terminated polyamic acid (e.g., a polyamic acid of Structure(VIIb)) is produced.

The molar ratio of tetracarboxylic acid dianhydride component(s) todiamine component(s) can range from 0.8 to 0.99 and can have a directeffect on final molecular weight of polyamic acid and polyimide preparedby imidization of the polyamic acid. In some embodiments, the molarratio is selected such that the polyamic acid at the end of the reactionhas a weight average molecular weight (Mw) of at least about 10,000Daltons (e.g. at least about 20,000 Daltons, at least about 30,000Daltons, at least about 40,000 Daltons, or at least about 50,000Daltons) and/or at most about 90,000 Daltons (e.g. at most about 80,000Daltons, at most about 70,000 Daltons, at most about 60,000 Daltons).

Those skilled in the art will understand that there are multiplesynthetic pathways to convert polyamic acids (e.g., those of Structures(VIIa) and (VIIb)) to the polyimide polymers of this disclosure. Forexample, one pathway is to imidize polyamic acids of Structures (VIIa)and (VIIb) using chemical or thermal imidization techniques to formpolyimides of Structure (VIIIa) or (VIIIb).

In some embodiments, the polyimide described herein can be end-capped byreaction of the terminal group (e.g., the terminal NH₂ in Structure(VIIa) or the terminal anhydride in Structure (VIIIb)) with a compoundhaving a functional group which is reactive with the terminal group andthen imidized. Alternatively, the end-capping reaction of the terminalgroup in Structure (VIIa) or (VIIIb) can be done after the chemical orthermal imidization.

Another synthetic pathway is to include in the polymerization reaction amonoamine or monoanhydride. In such embodiments, the end-cappingreaction is performed together with the polymerization reaction.

The thermal imidization can, for example, be performed in the solidstate at a temperature ranging from about 100° C. to about 400° C.(e.g., from about 200° C. to about 300° C., or about 250° C.). Inanother embodiment, the thermal imidization can be performed in asolution at a temperature ranging from about 100° C. to about 250° C.When the heat treatment is performed within this temperature range, theimidization reactivity can be controlled within a desired range,minimizing non-reacted polyamic acid. In some embodiments, the thermalimidization in this manner is best done before reaction of the polymerterminal groups.

The polyamic acid can also be dehydrated in an imidization reactionusing an azeotroping thermal procedure. An example of this reaction isdescribed in U.S. Pat. No. 5,478,915. For example, after the synthesisof the polyamic acid is complete, toluene is added, and the solution isazeotropically refluxed at 155° C., collecting the water in a Dean-Starktrap.

In some embodiments, the polyimide of Structure (VIIa) or (VIIIb) isproduced by chemical imidization. For example, a chemical imidizingagent (e.g., a dehydrating agent) can be added to the polyamic acid ofStructure (VIIa) or (VIIb). This chemical imidization agent can catalyzethe ring-closing dehydration process of the polyamic acid groups to formimide functionalities on the polymer backbone. If the polyamic acid isisolated after the synthesis, it can be re-dissolved in a compatiblesolvent. Normally, when a chemical imidization is employed, theimidization reaction takes place without isolation of the polyamic acid.

A suitable dehydrating agent can be used alone or in combination with anon-nucleophilic base to imidize the polyamic acid. Examples of suitabledehydrating agents include, but are not limited to, trifluoromethanesulfonic acid, methanesulfonic acid, p-toluenesulfonic acid,ethanesulfonic acid, butanesulfonic acid, perfluorobutanesulfonic acid,acetic anhydride, propionic anhydride, and butyric anhydride. If used,the non-nucleophilic base employed can be the same as or different froma non-nucleophilic base employed in the end-capping reaction. Examplesof suitable non-nucleophilic bases include, but are not limited to,pyridine, triethylamine, tripropylamine, tributylamine,dicyclohexylmethylamine, 2-methylpyridine, 2,6-lutidine, 3,5-lutidine,4-picoline, 4-dimethylaminopyridine (DMAP) and the like.

In some embodiments, the chemical imidization process is carried outwith a suitable dehydrating agent and a non-nucleophilic base at about60° C. to about 130° C. for about 6 hours to about 48 hours. Thedehydrating agent and non-nucleophilic base can be employed in equimolarconcentrations. In another embodiment, the molar ratio of dehydratingagent to non-nucleophilic base is from about 1.1 to about 10 (e.g., fromabout 1.25 to 5, or from about 1.5 to about 3.0). In one embodiment,about 90 mole % to 200 mole % of a dehydrating agent based on the totalamount of the polyamic acid present in the mixture is used to completethe imidization reaction. In some embodiments, 100 mole % to 160 mole %of a dehydrating agent is used to complete the imidization process.

Imidization to form a polyimide of Structure (VIIa) or (VIIIb) can beconfirmed by observation of characteristic absorptions in the infraredspectrum from 1770 and 1700 cm⁻¹ attributable to the imide ringstructure.

The terminal NH₂ groups of the polymers of Structures (VIIa) and (VIIa)can be optionally end-capped by reaction with an end-capping compoundhaving a functional group which is reactive to an amine. Examples ofsuch end-capping compounds include, but are not limited to, acidchloride compounds, dicarboxylic acid anhydrides, epoxide compounds, andisocyanate compounds. In some embodiments, end-capping compounds can bethose containing at least one second functional group selected from asubstituted or unsubstituted alkenyl group (e.g., a C₂-C₆ linear alkenylgroup) and a substituted or unsubstituted alkynyl group (e.g., a C₂-C₆linear alkynyl group). Examples of substituted alkenyl groups include,but are not limited to, acrylates, methacrylates, stilbenes, and vinylethers. Examples of substituents on alkynyl groups include, but are notlimited to, alkyl (e.g., Me or Et), aryl (e.g., phenyl or substitutedphenyl), alkanoyl (e.g., acetyl) and aroyl (e.g., benzoyl).

Examples of end-capping compounds having a functional group reactive tothe terminal NH₂ groups that also have at least one second functionalgroup selected from a substituted or unsubstituted alkenyl group and asubstituted or unsubstituted alkynyl group include, but are not limitedto, the following compounds:

When anhydrides are employed as the reactive functional group to end-capthe polymers of Structures (VIIa) and (VIIa), end groups containing amicacids are produced. Polyamic acids terminating polymers of Structure(VIIa) can be imidized when the backbone polyamic acids are imidized.When monoanhydrides are employed as the reactive functional group toend-cap an amino-terminated polyimide, the terminated group will be apolyamic acid. These terminal polyamic acids can imidize spontaneouslyor during isolation and drying, or can easily be imidized with mild heator with a minimal of dehydrating agent.

In some embodiments, the monoanhydride suitable for preparing the endcapped polyamic acids or polyimides contains a “masked” maleic anhydridegroup, which after conversion of the anhydride group to an imide group,becomes a “masked” maleimide group. This terminal imide group is able toundergo a cycloreversion reaction (e.g., a retro-Diels-Alder reaction)to unmask the maleimide group. A polyimide polymer containing maleimidegroups as end-cap groups can react with a reactive functional compound(RFC) (e.g., a compound containing at least two thiol groups) to form across-linked polyimide.

Examples of monoanhydrides that can undergo a cycloreversion reactioninclude, but are not limited to, compounds described by Structure IX:

where G is —O—, —(NR²⁵)—, —[C(R²⁶)═C(R²⁷)]—, or —[C═C(R²⁸)₂]—, in whicheach of R²⁵, R²⁶, R²⁷, and R²⁸, independently, is H, a substituted orunsubstituted C₁-C₁₂ linear, branched, monocyclic or polycyclic alkylgroup, or a substituted or unsubstituted phenyl group, and each of R²¹,R²², R²³ and R²⁴, independently, is H, a substituted or unsubstitutedC₁-C₁₂ linear, branched, monocyclic or polycyclic alkyl group, asubstituted or unsubstituted phenyl group, OR²⁹, CH₂OR³⁰, CH₂OC(═O)R³¹,CH₂C(═O)OR³², CH₂NHR³³, CH₂NHC(═O)R³⁴, CH₂C(═O)N(R³⁵)₂, C(═O)OR³⁶, inwhich each of R²⁹, R³⁰, R³¹, R³², R³³, R³⁴, R³⁵and R³⁶, independently,is H or a substituted or unsubstituted C₁-C₆ linear, branched, ormonocyclic alkyl group.

Examples of specific suitable monoanhydrides of Structure IX include,but are not limited to, the following compounds:

Other examples of monoanhydrides of Structure IX have been described,for example, in U.S. Application Publication No. 2014-0343199, thecontents of which are hereby incorporated by reference.

The terminal anhydride groups of the anhydride terminated polymers ofStructures (VIIb) and (VIIIb) can be optionally end-capped by reactionwith a compound having a functional group which is reactive with ananhydride. Examples of such functional groups include, but are notlimited to, amino, hydroxyl, and thiol groups. In some embodiments,end-capping compounds are those having at least one second functionalgroup selected from a substituted or unsubstituted alkenyl group and asubstituted or unsubstituted alkynyl group.

Examples of end-capping compounds containing reactive groups include,but are not limited to, the following compounds:

In some cases, a non-nucleophilic base can be used to facilitate thereaction between end-capping compounds and the terminal anhydridegroups. Examples of suitable non-nucleophilic bases include, but are notlimited to, pyridine, triethylamine, tripropylamine, tributylamine,dicyclohexylmethylamine, 2-methylpyridine, 2,6-lutidine, 3,5-lutidine,4-picoline, 4-dimethylaminopyridine (DMAP) and the like.

When the anhydride terminated polymers of Structures (VIIb) and (VIIIb)are end-capped with an amine containing compound, end groups containingamic acids are produced. In this situation, when the polyamic acids areimidized, the endcap is imidized as well. The polyamic acid resultingfrom the end-capping of anhydride terminated polyimides of Structure(VIIIb) with an amine containing compound can be isolated.Alternatively, the terminal polyamic acid can be imidized thermally orchemically during or after the formation of the polyimide.

In some embodiments, the resulting polyimides of the present disclosurecan be isolated by precipitation into water and/or an organic solvent,recovered by filtration, and dried. In another embodiment, the polyimideof the present disclosure can be isolated by addition of its solution toa combination of water and a suitable water-immiscible solvent. Becauseof the lower polarity nature of the monomer moieties in the polyimidepolymer, higher solubility in lower polarity water immiscible solventsallows the polyimide of this disclosure, unlike most polyimides, to beextracted from the higher polarity reaction solvent/water mixture. Thisextracted polymer solution can be purified by washing with waterfollowed by separation of the water layer, distillation of variousvolatile compounds, and subsequent extraction into a higher boilingsolvent.

The reactive functional compound (RFC) (component B) in thephotosensitive polymeric composition or the photosensitive polymericlayer generally helps generate a contrast in the dissolution rate of thefilm prepared from the photosensitive composition described hereinbefore and after exposure. In some embodiments, the RFC possesses atleast one (e.g., at least two or at least three) functional groupscapable of reacting with other RFC compounds or with the optionalterminal functional group on the polyimide polymer (e.g., the secondfunctional group of the end-capping reagent, which becomes a part of thepolyimide polymer described above after the end-capping reaction). TheRFC can be a monomer or an oligomer. The oligomer can contain two ormore monomer units and is capable of further reactions to beincorporated in the final polyimide polymer. Examples of such monomerunits/oligomers are based on one or more of the following types:(meth)acrylates, esters, vinyl compounds (e.g., vinyl alcohol),urethanes, ureas, imides, amides, carboxazoles, carbonates, pyranoses,siloxanes, urea-formaldehydes and melamine-formaldehydes. As usedherein, the term “(meth)acrylate” include both acrylate compounds andmethacrylate compounds. In some embodiments, the RFC contains at leastone terminal and/or pendant reactive functional group capable ofradical, or thermal reaction with the at least one second functionalgroup. In one embodiment, the reactive functional group on the RFCincludes a double or triple bond.

Suitable examples of reactive functional groups on the RFC include, butare not limited to, a vinyl group, an allyl group, a vinyl ether group,a propenyl ether group, a (meth)acryloyl group, a —SiH group and a —SH(thiol) group.

In one embodiment, a suitable example of an RFC includes, but is notlimited to, an urethane acrylate oligomer. The term “urethane acrylateoligomer” refers to a class of compounds that contain urethane linkagesand have (meth)acrylate (e.g., acrylate or methacrylate) functionalgroups such as urethane multi(meth)acrylate, multiurethane(meth)acrylate, and multiurethane multi(meth)acrylate. Types of urethane(meth)acrylate oligomers have been described by, for example, Coady etal., U.S. Pat. No. 4,608,409 and by Chisholm et al., U.S. Pat. No.6,844,950. Other specific examples of RFC include 1,6-hexanedioldi(meth)acrylate, tetraethyleneglycol di(meth)acrylate, divinylbenzene,ethoxylated bisphenol-A-di(meth)acrylate, diethylene glycol bis(allylcarbonate), trimethylolpropane tri(meth)acrylate, ditrimethylolpropanetetra(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritoltetra(meth)acrylate, dipentaerythritol penta-/hexa-(meth)acrylate,isocyanurate tri(meth)acrylate, bis(2-hydroxyethyl)-isocyanuratedi(meth)acrylate, 1,3-butanediol tri(meth)acrylate, 1,4-butanedioltri(meth)acrylate, methyl (meth)acrylate, butyl (meth)acrylate,cyclohexyl (meth)acrylate, benzyl(meth)acrylate, neopentyl glycoldi(meth)acrylate, (meth)acrylate modified-urea-formaldehyde resins,(meth)acrylate modified melamine-formaldehyde resins and (meth)acrylatemodified cellulose.

Examples of RFC compounds containing thiol groups include, but are notlimited to, trimethylolpropane tris(mercaptoacetate), pentaerythritoltetrakis(mercaptoacetate), dipentaerythritolhexakis(3-mercaptopropionate), and ethoxylated trimethylolpropanetri-3-mercaptopropionate. Examples of RFC compounds containing vinylether groups include, but are not limited to, 1,4-butanediol divinylether, 1,4-cyclohexanedimethanol divinyl ether, di(ethylene glycol)vinyl ether, poly(ethylene glycol) divinyl ether, andbis[4-(vinyloxy)butyl] (4-methyl-1,3-phenylene)biscarbamate. One exampleof a RFC compound containing a SiH group is octasilane POSS® SH1310available from Hybrid Plastics.

In some embodiments, a photoinitiator (i.e., component (C)) in thephotosensitive polymeric composition or the photosensitive polymericlayer of the dry film structure is a compound capable of initiating areaction between the functional groups of the reactive functionalcompound (RFC) or between a functional group of an RFC and the secondfunctional group of optionally end-capped polymers, when thecomposition, or a portion of the composition, is exposed to actinicradiation. Some photoinitiators used in the composition function bygenerating free radicals after absorbing light at the wavelength ofexposure.

Specific examples of initiators that generate free radicals when exposedto high energy radiation (also known as photoinitiators) include, butare not limited to, NCI-831 (Available from ADEKA Corp.),1,8-bis[9-(2-ethylhexyl)-6-nitro-9H-carbazol-3-yl]-1,8-bis(O-acetyloxime),2-hydroxy-2-methyl-1-phenylpropan-1-one, 1-hydroxycyclohexyl phenylketone (Irgacure 184 from BASF), a blend of1-hydroxycyclohexylphenylketone and benzophenone (Irgacure 500 fromBASF), 2,4,4-trimethylpentyl phosphine oxide (Irgacure 1800, 1850, and1700 from BASF), 2,2-dimethoxyl-2-acetophenone (Irgacure 651 from BASF),bis(2,4,6-trimethyl benzoyl)phenyl phosphine oxide (Irgacure 819 fromBASF), 2-methyl-1-[4-(methylthio)phenyl]-2-morphorinopropane-1-on(Irgacure 907 from BASF), (2,4,6-trimethylbenzoyl)diphenyl phosphineoxide (Lucerin TPO from BASF), ethoxy(2,4,6-trimethylbenzoyl)phenylphosphine oxide (Lucerin TPO-L from BASF), a blend of phosphine oxide,hydroxy ketone and a benzophenone derivative (ESACURE KTO46 fromSartomer), 2-hydroxy-2-methyl-1-phenylpropane-1-on (Darocur 1173 fromMerck), benzophenone, 2-chlorothioxanthone, 2-methylthioxanthone,2-isopropylthioxanthone, benzodimethyl ketal,1,1,1-trichloroacetophenone, diethoxyacetophenone, m-chloroacetophenone,propiophenone, anthraquinone, dibenzosuberone and the like.

Specific examples of nonionic-type photoinitiators are(5-toluylsulfonyloxyimino-5H-thiophen-2-ylidene)-2-methylphenyl-acetonitrile(Irgacure121 from BASF), phenacyl p-methylbenzenesulfonate, benzoinp-toluenesulfonate, (p-toluene-sulfonyloxy)methylbenzoin,3-(p-toluenesulfonyloxy)-2-hydroxy-2-phenyl-1-phenylpropyl ether,N-(p-dodecylbenzenesulfonyloxy)-1,8-naphthalimide,N-(phenyl-sulfonyloxy)-1,8-napthalimide,bis(cyclohexylsulfonyl)diazomethane,1-p-toluenesulfonyl-1-cyclohexylcarbonyldiazomethane, 2-nitrobenzylp-toluenesulfonate, 2,6-dinitrobenzyl p-toluenesulfonate, and2,4-dinitrobenzyl p-trifluoromethylbenzenesulfonate and the like.

Alternatively, a combination of a photosensitizer and an initiator(e.g., an initiator not activated by actinic radiation) may be used inthe photosensitive composition. In this alternative, a photosensitizerabsorbs the light and transfers energy to the initiator to startreactions with the RFC. Examples of photosensitizers include, but arenot limited to, 9-methylanthracene, anthracenemethanol, acenaphthylene,thioxanthone, methyl-2-naphthyl ketone, 4-acetylbiphenyl, and1,2-benzofluorene.

Specific examples of initiators that can be activated by a sensitizerinclude, but are not limited to, benzoyl peroxide, cyclohexanoneperoxide, lauroyl peroxide, tert-amyl peroxybenzoate, tert-butylhydroperoxide, dicumyl peroxide, cumene hydroperoxide, succinic acidperoxide, di(n-propyl)peroxydicarbonate, 2,2-azobis(isobutyronitrile),2,2-azobis(2,4-dimethylvaleronitrile), dimethyl-2,2-azobisisobutyrate,4,4-azobis(4-cyanopentanoic acid), azobiscyclohexanecarbonitrile,2,2-azobis(2-methylbutyronitrile) and the like.

In some embodiments, the photosensitive polymeric composition describedherein can include at least one organic solvent. Suitable examples oforganic solvents include, but are not limited to, gamma-butyrolactone(GBL), N-methyl-2-pyrrolidone (NMP), dimethylimidazolidinone,N-methylcaprolactam, N-methylpropionamide, N,N-dimethylacetamide (DMAc),dimethyl sulfoxide (DMSO), N,N-dimethylformamide (DMF),N,N-diethylfornamide, diethylacetamide, methyl ethyl ketone (MEK),methyl isobutyl ketone (MIBK), 2-heptanone, cyclopentanone (CP),cyclohexanone, n-butyl acetate (nBA), propylene glycol methyl etheracetate (PGMEA), propylene glycol methyl ether (PGME), ethyl lactate(EL), propyl lactate, 3-methyl-3-methoxybutanol, tetralin, isophorone,ethylene glycol monobutyl ether, diethylene glycol monoethyl ether,diethylene glycol monoethyl ether acetate, diethylene glycol dimethylether, diethylene glycol methylethyl ether, triethylene glycol monoethylether, dipropylene glycol monomethyl ether, methyl 3-methoxypropionate,ethyl 3-ethoxypropionate, diethyl malonate, ethylene glycol1,4:3,6-dianhydrosorbitol, 2,5-dimethyl ether (2,5-dimethylisosorbide),1,4:3,6-dianhydrosorbitol 2,5-diethyl ether (2,5-diethylisosorbide) andmixtures thereof. Preferred solvents are gamma-butyrolactone (GBL),cyclopentanone (CP), cyclohexanone, isosorbide dimethyl), ethyl lactate(EL) and dimethylsulfoxide (DMSO). These solvents can be usedindividually or in combination.

In general, the polyimide polymer described herein can be soluble in theorganic solvent described above. In some embodiments, the polyimidepolymer can have a solubility in one of the organic solvents describedin the preceding paragraph of at least about 50 mg/mL (e.g., at leastabout 100 mg/mL or at least about 200 mg/mL) at 25° C.

In some embodiments, the photosensitive polymeric layer can optionallyinclude at least one solvent. The solvent in the photosensitivepolymeric layer can be the residual of the solvent in the photosensitivepolymeric composition described above. In general, the amount of solventin the photosensitive polymeric layer of the dry film of this disclosuredepends on drying time and temperature. In some embodiments, the amountof solvent is at least about 0.5 weight % (e.g., at least about 1 weight%, at least about 2 weight %, at least about 3 weight %, at least about4 weight %, or at least about 4.5 weight %) and/or at most about 20weight % (e.g., at most about 17 weight %, at most about 14 weight %, atmost about 11 weight %, at most about 8 weight %, or at most about 5weight %) of the entire weight of the photosensitive polymeric layer ofdry film.

The photosensitive polymeric layer can have a thickness from at mostabout 5 μm (e.g., at most about 4 μm, or at most about 3 μm) to at leastabout 1 μm (e.g., at least about 2 μm, or at least about 3 μm).

In some embodiments, the amount of polyimide (component (A)) is at leastabout 5 weight % (e.g., at least about 10 weight %, at least about 20weight %, at least about 30 weight %, or at least about 40 weight %)and/or at most about 95 weight % (e.g., at most about 90 weight %, atmost about 85 weight %, at most about 80 weight %, or at most about 75weight %) of the entire weight of the photosensitive polymericcomposition.

In some embodiments, the amount of component (B) (RFC) having at leastone reactive functional group is at least about 1 weight % (e.g., atleast about 4 weight %, at least about 8 weight %, at least about 12weight %, at least about 16 weight %, or at least about 20 weight %)and/or at most about 50 weight % (e.g., at most about 45 weight %, atmost about 40 weight %, at most about 35 weight %, or at most about 30weight %) of the entire weight of the photosensitive polymericcomposition.

In some embodiments, the amount of reactive functional compound (RFC) isat most about 60 wt % (e.g., at most about 55 wt %, at most about 50 wt%, at most about 45 wt %, at most about 40 wt %, or at most about 35 wt%) of the amount of the polyimide polymer. If the amount of reactivefunctional compound (RFC) is higher than about 60 wt % of the amount ofthe polyimide polymer, it is believed that the mechanical properties aswell as chemical resistance of the film made from such a dry film cansuffer and coating defects and tackiness of film due to lower viscositycan be observed.

In some embodiments, the amount of reactive functional compound (RFC) isat least about 10 wt % (e.g., at least about 15 wt %, at least about 20wt %, at least about 25 wt %, or at least about 30 wt %) of the amountof the polyimide polymer. If the amount of reactive functional compound(RFC) is less than about 10 wt % of the amount of the polyimide polymer,it is believed that there can be poor contrast between exposed andunexposed areas of the film made from such a dry film and lithographicperformance of the film will suffer greatly.

In some embodiments, the amount of component (C) (photoinitiator) is atleast about 0.0001 weight % (e.g., at least about 0.01 weight %, atleast about 0.1 weight %, or at least about 1 weight %) and/or at mostabout 10 weight % (e.g., at most about 7 weight %, at most about 5weight %, or at most about 3 weight %) of the entire weight of thephotosensitive polymeric composition.

The photosensitive polymeric composition or the photosensitive polymericlayer of the dry film structure of this disclosure may optionallycontain other additives including, but not limited to, adhesionpromoters, surfactants, nanoparticles, and plasticizers. The amounts ofthese additional additives can range from 0 wt % to about 15 wt % basedon the entire weight of the photosensitive polymeric composition or thephotosensitive polymeric layer.

Suitable adhesion promoters are described in “Silane Coupling Agent”Edwin P. Plueddemann, 1982 Plenum Press, New York. Classes of adhesionpromoters include, but are not limited to, vinylalkoxysilanes,methacryloxyalkoxyysilanes (e.g.,3-methacryloxypropyldimethoxymethylsilane, and3-methacryloxypropyltrimethoxysilane), mercaptoalkoxysilanes,aminoalkoxysilanes, epoxyalkoxysilanes and glycidyloxyalkoxysilanes.Examples of suitable adhesion promoters include, but are not limited to,gamma-aminopropyltrimethoxysilane,gamma-glycidyloxypropylmethyldimethoxysilane,gamma-glycidyloxypropyl-methyldiethoxysilane,glycidyloxypropyltrimethoxysilane, andgamma-mercaptopropyl-methyldimethoxysilane.

In some embodiments, the adhesion promoter contains a silicon compoundwithout a thiol group. In some embodiments, the adhesion promotercontains a silicon compound without an acrylic moiety. In someembodiments, the adhesion promoter contains a silicon compound withoutan epoxy group.

The concentration of the optional adhesion promoter, if employed, rangesfrom at least about 0.1% by weight (e.g., at least about 0.2% by weightor at least about 0.3% by weight) to at most about 5% by weight (e.g.,at most about 1.5% by weight or at most about 1% by weight) of thepolymeric composition.

The photosensitive polymeric composition or the photosensitive polymericlayer of the dry film structure of this disclosure can also optionallycontain at least one surfactant. If a surfactant is employed, it can beadded from at least about 0.001% by weight (e.g., at least about 0.05%by weight or at least about 0.1% by weight) to at most about 2% byweight (e.g., at most about 1.5% by weight or at most about 1% byweight) of the first polymeric layer compositions. Examples of suitablesurfactants include, but are not limited to, the surfactants describedin JP-A-62-36663, JP-A-61-226746, JP-A-61-226745, JP-A-62-170950,JP-A-63-34540, JP-A-7-230165, JP-A-8-62834, JP-A-9-54432 andJP-A-9-5988.

The photosensitive polymeric composition or the photosensitive polymericlayer of the dry film structure of the present disclosure can optionallycontain at least one plasticizer. The amount of the optionalplasticizer, if employed, can range from at least about 1% by weight(e.g., at least about 1.5% by weight or at least about 2% by weight) toat most about 20% by weight (e.g., at most about 10% by weight or atmost about 5% by weight) of the first polymeric layer composition.

In some embodiments, the photosensitive polymeric composition or thephotosensitive polymeric layer of the dry film structure of thisdisclosure can further include at least one nanoparticle (e.g., aplurality of nanoparticles). The nanoparticle can be made from one ormore polymers, inorganic materials, and/or metals. The nanoparticlessuitable for this application are preferably less than 200 μm indiameter and are compatible with the other components of thecompositions of this disclosure. Examples of such nanoparticles arefound, e.g., in U.S. Pat. Nos. 6,291,070 and 6,844,950, the contents ofwhich are hereby incorporated by reference. Without wishing to be boundby theory, it is believed that the nanoparticles can improve themechanical properties (e.g., CTE) and electrical properties (e.g.,dielectric properties) of the polymeric layer of the dry film structuremade by such photosensitive compositions.

Examples of nanoparticles include silica, alumina, titania, zirconia,hafnium oxide, CdSe, CdS, CdTe, CuO, zinc oxide, lanthanum oxide,niobium oxide, tungsten oxide, strontium oxide, calcium titanium oxide,sodium titanate, and potassium niobate. The nanoparticles can be surfacetreated or untreated nanoparticles.

In some embodiments, the photosensitive compositions of the presentdisclosure include one or more additional polymers which form acontinuous phase with the polyimide polymer described above. Suitableexamples of the additional polymers include, but are not limited to,polyamic acids, polyamic esters, polyesters, polyamides,polyhydroxyamides, polyetherimides, polyarylenes, polyethers andpolyarylsulfides. These additional polymers may contain reactive groups(e.g. unsaturated groups) at their termini and/or along their backbone.In some embodiments, the additional polymer is added in amounts of fromat least about 0.5 weight % (e.g., at least about 1 weight % or at leastabout 5 weight %) to at most about 20 weight % (e.g., at most about 15weight % or at most about 10 weight %) relative to the polyimidepolymer(s). In some embodiments, the compositions of the presentdisclosure are substantially free of a polymer which forms adiscontinuous phase with the polyimide polymer described above.

In some embodiments, this disclosure features methods of preparation ofa dry film structure. The method includes: (a) coating a carriersubstrate with a photosensitive polymeric composition described hereinto form a coated composition, (b) drying the coated composition to forma photosensitive polymeric layer, and (c) optionally applying aprotective layer to the photosensitive polymeric layer to form a dryfilm structure.

In some embodiments, the carrier substrate is a single or multiple layerfilm, which optionally has undergone treatment to modify the surface ofthe film that will contact the photosensitive polymeric layer of the dryfilm structure. In some embodiments, one or more layers of a multilayercarrier substrate can contain particles. Examples of particles include,but are not limited to, inorganic particles such as silicon dioxideparticles (aggregated silica and the like), calcium carbonate particles,alumina particles, titanium oxide particles, and barium sulfateparticles; organic particles such as crosslinked polystyrene particles,acrylic particles, and imide particles; and their mixtures. Withoutwishing to be bound by theory, it is believed that the particles canimprove the adhesion properties of the carrier substrate, and canimprove the uniformity of the photosensitive polymeric layer coated onthe carrier substrate.

In some embodiments, the carrier substrate has excellent opticaltransparency and is substantially transparent to actinic irradiationused to form a relief pattern in the photosensitive polymeric layer. Insome embodiments, the carrier substrate can possess low surfaceroughness. The carrier substrate in general should be sufficientlystrong and they should be insoluble in the solvent used to form thepolymeric layer. The carrier substrate can be removed from the remainderof the dry film structure (e.g., the photosensitive polymeric layer) insubsequent use, or can form part of the final structure of thefabricated device. In situations where the carrier substrate iseventually removed from the final device, such as by peeling, adhesionbetween the carrier substrate and the photosensitive polymeric layershould be weak enough to allow for ease of separation. In suchembodiments, the carrier substrate can include a release layer on thesurface to be coated by the photosensitive polymeric layer to facilitateremoval of the carrier substrate. In cases in which the carriersubstrate is part of the final device, adhesion should be high toprevent peeling of the carrier substrate.

As specific examples of the carrier substrate, there may be variousplastic films such as polyethylene terephthalate (PET), polyethylenenaphthalate, polypropylene, polyethylene, cellulose tri-acetate,cellulose di-acetate, poly(metha)acrylic acid alkyl ester,poly(metha)acrylic acid ester copolymer, polyvinylchloride, polyvinylalcohol, polycarbonate, polystyrene, cellophane, polyvinyl chloridecopolymer, polyamide, polyimide, vinyl chloride-vinyl acetate copolymer,polytetrafluoroethylene, polytrifluoroethylene, and the like. Inaddition, a combination material containing two or more plastic films ortwo or more polymers can be used. Polyethylene terephthalate (PET) filmhaving excellent optical transparency is particularly preferable. Thethickness of the carrier substrate can be in the range of at least about10 μm (e.g., at least about 15 μm, at least about 20 μm, at least about30 μm, at least about 40 μm, at least about 50 μm or at least about 60μm) to at most about 150 μm (e.g., at most about 140 μm, at most about120 μm, at most about 100 μm, at most about 90 μm, at most about 80 μm,or at most about 70 μm). The Young's modulus of the carrier substratecan be in the range of at least about 100 MPa (e.g., at least about 150MPa, at least about 200 MPa, or at least about 250 MPa) to at most about500 MPa (e.g., at most about 450 MPa, at most about 400 MPa, or at mostabout 350 MPa).

The carrier substrate can be used with or without corona treatment.Corona is ionized air created by discharging high frequency high voltageenergy across a metal or insulated electrode. This electrode ispositioned over a grounded roll. The corona treatment of films canoptimize surfaces for adhesion by removing surface contaminants,creating bonding sites and raising the surface energy. In someembodiments, corona treatment can be done during winding of the carriersubstrate film to form a roll by passing the film through a coronaprocess. This produces pretreated corona film. Such corona treatedcarrier substrate films are commercially available. Another option is“online corona treatment” where the carrier substrate film is passedthrough a corona chamber just before coating of the photosensitivepolymeric layer composition onto the carrier substrate. On line coronatreatment of carrier substrates can improve print quality, eliminatespinholing in coating, and increases dry film structure productivity.

The coating method to form the photosensitive polymeric layer of the dryfilm structure is not particularly limited. For example, methods such asspray coating, roll coating, rotation coating, slit coating, compressioncoating, curtain coating, die coating, wire bar coating, and knifecoating can be used to form the photosensitive polymeric layer. Thedrying temperature used to form the photosensitive polymeric layer canvary according to the components, the organic solvent, and the contentratio. In some embodiments, drying is carried out at a temperature of atleast about 60° C. (e.g., at least about 65° C., at least about 70° C.or at least about 75° C.) to at most about 120° C. (e.g., at most about105° C., at most about 90° C. or at most about 85° C.) for at leastabout 30 seconds (e.g., at least about 1 minute, at least about 2minutes, at least about 4 minutes or at least about 6 minutes) to atmost about 15 minutes (e.g., at most about 12 minutes, at most about 10minutes, or at most about 8 minutes). An example of the drying means isa convection oven using hot air, but any suitable heating means can beemployed.

In some embodiments, melt viscosity and melting point can be importantthermal properties of the above described photosensitive polymericlayer. Both of these properties can be critical for effective laminationof the dry film structure onto a substrate.

In some embodiments, the dry film structure contains a photosensitivepolymeric layer having a melt viscosity of at least about 10 poise(e.g., at least about 20 poise, at least about 30 poise, at least about40 poise or at least about 50 poise) and/or at most 150 poise (e.g., atmost about 140 poise, at most about 130 poise, at most about 120 poise,at most about 110 poise, at most about 100 poise or at most about 90poise) at a temperature from about 60° C. to about 140° C. Withoutwishing to be bound by theory, it is believed that, when melt viscosityof the photosensitive polymeric layer is too low, over-flowing of thephotosensitive polymeric layer can occur during lamination. This resultsin inconsistent film thickness of the laminated film and contaminationof the backside of substrate. When the melt viscosity is too high,polymer flow can be unusually slow which results in voids andair-bubbles in the layer thus formed. Moreover, if the carrier substrateis patterned, low polymer flow can cause incomplete and improper fillingof the patterns.

In some embodiments, the photosensitive polymeric layer has a meltingpoint of at least about 60° C. (e.g., at least 65° C., at least about70° C., at least about 75° C., or at least about 80° C.) and/or at mostabout 140° C. (e.g. at most about 135° C., at most about 130° C., atmost about 125° C., or at most about 120° C.). Without wishing to bebound by theory, it is believed that, when the melting point of thephotosensitive polymeric layer is too low, formation of a dry film canbe hindered to such a degree that the formation of the dry film stack,typically by a continuous process, is hindered. When the melting pointis too high, a high temperature is needed during lamination of thephotosensitive polymeric layer and the carrier substrate and can causethe carrier substrate to be melted, thereby ruining the dry film stack.In addition, when a photosensitive polymeric layer with a high meltingpoint is used in a lower temperature lamination process, thephotosensitive polymeric layer can have poor adhesion with thesubstrate.

In some embodiments, the dry film structure includes a protective layer(e.g., a protective film or a protective cover sheet) so that thephotosensitive polymeric layer is disposed between the protective layerand the carrier substrate. The protective layer can protect thephotosensitive polymeric layer during transit and storage, and keepingthe tacky photosensitive polymeric layer from sticking to itself. Insome embodiments, the protective layer is a single or multiple layerfilm which optionally has undergone treatment to modify the surface ofthe film that will contact the photosensitive polymeric layer of the dryfilm structure. The protective layer can be made from polyethylene,polypropylene, or any other suitable polymer. In some embodiments,adhesion of the protective layer to the photosensitive polymeric layeris less than that of the carrier substrate to the photosensitivepolymeric layer. This allows for easy separation of the protective layerfrom the photosensitive polymeric layer without also separating thephotosensitive polymeric layer from the carrier substrate. Theprotective layer can be laminated to the photosensitive polymeric layerby a roll compression method.

In some embodiments, the protective layer can have a Young's modulus inthe range of at least about 100 MPa (e.g., at least about 150 MPa, atleast about 200 MPa, or at least about 250 MPa) to at most about 500 MPa(e.g., at most about 450 MPa, at most about 400 MPa, or at most about350 MPa).

In general, the dry film structure described herein can be used tolaminate the photosensitive polymeric layer to a substrate (e.g., anelectronic substrate). In some embodiments, the photosensitive polymericlayer of the dry film structure can be laminated to any type ofsubstrates (e.g., electronic substrates) using a differential pressurelaminator where vacuum, heat, and pressure are combined for voidlesslamination. Examples of suitable electronic substrates include a siliconsubstrate, a copper substrate, an aluminum substrate, a silicon oxidesubstrate, a silicon nitride substrate, a glass substrate, an organiclaminate substrate, or a dielectric material substrate. For example, theprotective layer of the dry film structure can be peeled off, and theremainder of the structure (e.g., a photosensitive polymeric layer on acarrier substrate) can then be cut to the substrate size. As anotherexample, the dry film structure can be cut to the substrate size andthen the protective layer can be peeled off to laminate thephotosensitive polymeric layer onto a substrate. In some embodiments,these substrates, pre-laminated either manually or with the assistanceof currently available dispensing equipment, are placed on the slidemounted platen or positioned in a chamber. Substrates varying inthickness and geometry can be intermixed to increase throughput. Thesubstrate can then be exposed to a vacuum dwell for a time determined byan integral precision digital timer. Following this period, a preheatedsilicone rubber diaphragm can descend onto the work piece. This actioncan close the small gap below the spring-mounted platen assembly andprovides direct thermal contact with the lower heat platen. Thetemperatures of both the upper and lower heated platens can becontrolled independently by integral temperature controllers.Differential pressure laminator generally permits the addition ofpositive pressure above the diaphragm, increasing the effectivelamination pressure dramatically. The pressure dwell period can beadjusted with a timer identical to that employed in the vacuum dwell.Upon completion of a cycle, the drawer mechanism can be retracted andthe laminated substrate can be removed for further processing.

In some embodiments, the photosensitive polymeric layer can be laminatedto a substrate through a vacuum lamination at 60° C. to 140° C. afterpre-laminating of the photosensitive polymeric layer of the dry filmstructure with a plane compression method or a hot roll compressionmethod. When the hot roll lamination is employed, the dry film structurecan be placed into a hot roll laminator, the protective layer can bepeeled away from the photosensitive polymeric layer/carrier substrate,and the photosensitive polymeric layer can be brought into contact withand laminated to a substrate using rollers with heat and pressure.

In some embodiments, the lamination temperature used in the laminationprocess described above is at least about 50° C. (e.g., at least about70° C., at least about 80° C., at least about 90° C., or at least about100° C.) to at most about 220° C. (e.g., at most about 190° C., at mostabout 170° C., at most about 160° C., at most about 130° C., or at mostabout 110° C.). The pressure used in the lamination process describedabove is at least about 1.5 psi (e.g., at least about 3 psi, at leastabout 5 psi, at least about 10 psi, at least about 15 psi, or at leastabout 20 psi) to preferably at most about 70 psi (e.g., at most about 60psi, at most about 50 psi, at most about 40 psi, or at most about 30psi). The vacuum used in the lamination process described above can beat least about 0.2 Torr to at most about 5 Torr. The speed of the rollerused in the lamination process described above can be at least about 1cm/min (e.g., at least about 5 cm/min, at least about 10 cm/min, atleast about 25 cm/min, or at least about 50 cm/min) to at most about 600cm/min (e.g., at most about 500 cm/min, at most about 400 cm/min, atmost about 300 cm/min at most about 200 cm/min, or at most about 100cm/min).

In some embodiments, this disclosure features a process of forming alaminate. The process can include applying the dry film structure ontoan electronic substrate to form a laminate. In embodiments where theprotective layer is present in the dry film structure, the process canfurther include removing the protective layer from the dry filmstructure before applying the dry film structure onto the electronicsubstrate. In some embodiments, the process can further includeconverting the photosensitive polymeric layer into a patterned layer.The conversion can include exposing the photosensitive polymeric layerin the laminate to actinic radiation. In such embodiments, theconversion can further include removing the carrier substrate before orafter exposing the photosensitive polymeric layer. After thephotosensitive polymeric layer is exposed to actinic radiation, theconversion can further include developing the exposed photosensitivepolymeric layer to form a patterned layer having a relief pattern. Thedeveloping can include removing unexposed portions in the polymericlayer by using a developer to form a patterned layer having a reliefpattern and rinsing the relief pattern on the substrate with a solventor a mixture of solvents.

In some embodiments, the laminated photosensitive polymeric layer on anelectronic substrate is exposed through a desired patterned photomasksuch that the exposed areas in the photosensitive polymeric layer arecrosslinked. The cross-linking can occur between the molecules of thereactive functional compound, between the molecules of the reactivefunctional compound and the polyimide polymer, or between the moleculesof the polyimide polymer in the photosensitive polymeric layer. Examplesof active energy beams used for exposure include electron beams,ultraviolet light and X-ray, with ultraviolet light being preferable. Asa light source, it is possible to use a low-pressure mercury lamp,high-pressure mercury lamp, extra-high-pressure mercury lamp, halogenlamp, etc. The exposure dose is typically from about 100 mJ/cm² to about1,000 mJ/cm².

The carrier substrate can be removed by peeling before or after theexposure.

After the exposure, the photosensitive polymeric layer of the dry filmstructure can be heat treated to at least about 50° C. (e.g., at leastabout 55° C., at least about 60° C., or at least about 65° C.) to atmost about 100° C. (e.g., at most about 95° C., or at most about 90° C.,at most about 85° C., at most about 80° C., at most about 75° C., or atmost about 70° C.) for at least about 60 seconds (e.g., at least about65 seconds, or at least about 70 seconds) to at most about 90 seconds(e.g., at most about 85 seconds, or at most about 80 seconds). The heattreatment is usually accomplished by use of a hot plate or oven.

After the exposure, the photosensitive polymeric layer of the dry filmstructure can be developed to remove unexposed portions by using adeveloper. Development can be carried out by, for example, an immersionmethod or spraying method. Microholes and fine lines can be generated inthe photosensitive polymeric layer on the laminated substrate afterdevelopment.

Examples of developers for developing the photosensitive polymeric layerinclude an organic solvent or a mixture of organic solvents. Suitableexamples of organic solvents include, but are not limited to,gamma-butyrolactone (GBL), N-methyl-2-pyrrolidone (NMP),N-ethyl-2-pyrrolidone, N-butyl-2-pyrrolidone, N-formylmorpholine,dimethylimidazolidinone, N-methylcaprolactam, N-methylpropionamide,N,N-dimethylacetamide (DMAc), dimethyl sulfoxide (DMSO),N,N-dimethylformamide (DMF), N,N-diethylfornamide, diethylacetamide,methyl ethyl ketone (MEK), methyl isobutyl ketone (MIBK), 2-heptanone,cyclopentanone (CP), cyclohexanone, n-butyl acetate (nBA), propyleneglycol methyl ether acetate (PGMEA), propylene glycol methyl ether(PGME), ethyl lactate (EL), propyl lactate, 3-methyl-3-methoxybutanol,tetralin, isophorone, ethylene glycol monobutyl ether, diethylene glycolmonoethyl ether, diethylene glycol monoethyl ether acetate, diethyleneglycol dimethyl ether, diethylene glycol methylethyl ether, triethyleneglycol monoethyl ether, dipropylene glycol monomethyl ether, methyl3-methoxypropionate, ethyl 3-ethoxypropionate, diethyl malonate,ethylene glycol 1,4:3,6-dianhydrosorbitol 2,5-dimethyl ether(2,5-dimethylisosorbide), 1,4:3,6-dianhydrosorbitol 2,5-diethyl ether(2,5-diethylisosorbide) and mixtures thereof. Preferred solvents aregamma-butyrolactone (GBL), cyclopentanone (CP), cyclohexanone,2,5-dimethyl ether (2,5-dimethylisosorbide), ethyl lactate (EL), n-butylacetate (nBA) and dimethylsulfoxide (DMSO). These solvents can be usedindividually or in combination of two or more to improve the imagequality.

In some embodiments, the developer and the polyimide polymer in thephotosensitive polymeric layer can have a relative energy difference(RED) of at most about 3 (e.g., at most about 2.5, at most about 2, atmost about 1.5, or at most about 1) and/or at least about 0.1 (e.g., atleast about 0.2, at least about 0.5, at least about 0.7, or at leastabout 1). RED is the ratio of distance between Hansen parameters (Ra)and the interaction radius (Ro). In general, the lower the RED, thebetter solubility the polyimide polymer has in the solvent. Ra isdefined by the following formulation:(Ra)²=4(δ_(d2)−δ_(d1))²+(δ_(p2)−δ_(p1))²+(δ_(h2)−δ_(h1))² in whichδ_(d), δ_(p) and δ_(h) are respectively the energy between dispersion,intermolecular force and hydrogen bonds between molecules. Ra determinesthe radius of the sphere in Hansen space and its center is the threeHansen parameters. More detail on Hansen parameters can be found in thefollowing reference: “Hansen, Charles (2007). Hansen SolubilityParameters: A user's handbook, Second Edition. Boca Raton, Fla.: CRCPress. ISBN 978-0-8493-7248-3”.

In some embodiments, after the development, an optional rinse treatmentcan be carried out with an organic rinse solvent. Suitable examples oforganic rinse solvents include, but are not limited to, alcohols such asisopropyl alcohol, methyl isobutyl carbinol (MIBC), propylene glycolmonomethyl ether (PGME), and amyl alcohol; esters such as n-butylacetate (nBA), ethyl lactate (EL) and propylene glycol monomethyl etheracetate (PGMEA); ketones such as cyclopentanone (CP); and mixturesthereof. A rinse solvent can be used to carry out the rinse treatment toremove residues.

In some embodiments, after the development step or the optional rinsetreatment step, an optional baking step (i.e., a post development bake)can be carried out at a temperature ranging from at least about 120° C.(e.g., at least about 130° C., at least about 140° C., at least about150° C., at least about 160° C., at least about 170° C., or at leastabout 180° C.) to at most about 250° C. (e.g., at most about 240° C., atmost about 230° C., at most about 220° C., at most about 210° C., atmost about 200° C. or at most about 190° C.). The baking time is atleast about 5 minutes (e.g., at least about 10 minutes, at least about20 minutes, at least about 30 minutes, at least about 40 minutes, atleast about 50 minutes, or at least about 60 minutes) and/or at mostabout 5 hours (e.g., at most about 4 hours, at most about 3 hours, atmost about 2 hours, or at most about 1.5 hours). This baking step canremove residual solvent from the remaining photosensitive polymericlayer and can further crosslink the remaining photosensitive polymericlayer. Post development bake can be done in air or preferably, under ablanket of nitrogen and may be carried out by any suitable heatingmeans.

In some embodiments, the resulting baked photosensitive polymeric layerafter the baking step has a glass transition temperature of at leastabout 180° C. (e.g., at least about 190° C., at least about 200° C. orat least about 210° C.). In some embodiments, the resulting bakedphotosensitive polymeric layer after the baking step has a glasstransition of at most about 320° C. (e.g., at most about 310° C., atmost about 300° C. or at most about 290° C.). As used herein, the glasstransition temperature of the photosensitive polymeric layer is definedas the photosensitive inflection point on a thermo-mechanical analyzercurve plotting dimension change (μ) vs temperature.

In some embodiments, a high glass transition temperature for the bakedphotosensitive polymeric layer can be desirable to prevent film mobilityduring subsequent processing steps of device manufacture and subsequentdevice use for longer device life. Some manufacturing processing stepssuch as soldering require elevated temperatures. High glass transitiontemperature for the baked photosensitive polymeric layer can helpmaintain mechanical integrity of the resulting devices and can improveresistance to various chemicals and particularly to flux.

In general, the processes described above can be used to form an articleto be used in a semiconductor device. Examples of such articles includea semiconductor substrate, a flexible film for electronics, a wireisolation, a wire coating, a wire enamel, or an inked substrate.Examples of semiconductor devices that can be made from such articlesinclude an integrated circuit, a light emitting diode, a solar cell, anda transistor.

In some embodiments, this disclosure features a three dimensional objectcontaining at least one patterned film formed by a process describedherein. In some embodiments, the three dimensional object can includepatterned films in at least two stacks (e.g., at least three stacks).

In some embodiments, the processes described above can result in anarticle that includes an electronic substrate and a patterned layer(e.g., containing a relief pattern) laminated onto the electronicsubstrate, in which the patterned layer includes at least one polyimidepolymer. Without wishing to be bound by theory, it is believed that thepatterned layer thus formed can have a relatively small thickness with arelatively high resolution. For example, the patterned layer can have athickness of at most about 5 microns (e.g., at most about 4 microns orat most about 3 microns) and include at least one element having afeature size of at most about 3 microns (e.g. at most 2 microns).

In some embodiments, the patterned layer can have a Young's modulus ofat least about 1 GPa (e.g., at least about 2 GPa, at least about 3 GPa,at least about 4 GPa, or at least about 5 GPa) to at most about 20 GPa(e.g., at most about 18 GPa, at most about 16 GPa, at most about 14 GPa,at most about 12 GPa, or at most about 10 GPa). In some embodiments, thepatterned layer can have a Young's modulus that is about 200% to about300% as high as the Young's modulus of the photosensitive polymericlayer of the dry film structure.

In some embodiments, the dry film structure described above can furtherinclude a second polymeric layer containing at least one water solublepolymer. As defined herein, a “water-soluble” polymer refers to apolymer having a solubility of at least 5% by weight in water at 25° C.Examples of suitable water soluble polymer can be selected from a groupconsisting of poly(vinyl alcohol), poly(vinyl pyrrolidone), poly(acrylicacid) and the salts thereof, poly(methacrylic acid) and the saltsthereof, poly(acrylamide) and the salts thereof, poly(methacrylamide)and the salts thereof, poly(N-isopropylacrylamide) and the saltsthereof, poly (2-oxazoline), poly(ethylene oxide), poly(propyleneoxide), hydroxyethyl cellulose, hydroxypropyl cellulose, starch,polysaccharides, dextran, cyclodextran, and partially hydrolyzedpolyvinyl acetate.

In some embodiments, the second polymeric layer can be between thephotosensitive polymeric layer and the carrier substrate in the dry filmstructure. In such embodiments, when the dry film structure is laminatedonto an electronic substrate and the carrier substrate is removed, thelaminate thus formed includes the electronic substrate, thephotosensitive polymeric layer disposed thereupon, and the second watersoluble polymeric layer disposed on the photosensitive polymeric layer.In such embodiments, the second polymeric layer can improve the postexposure delay stability of the photosensitive polymeric layer byserving as a protecting layer. In such embodiments, the second polymericlayer can be removed by using water after exposure of the laminate tothe actinic radiation and before development.

In some embodiments, the second polymeric layer can be between thephotosensitive polymeric layer and the protective layer in the dry filmstructure. In such embodiments, when the dry film structure is laminatedonto an electronic substrate and the carrier substrate is removed, thelaminate thus formed includes the electronic substrate, the secondpolymeric layer disposed thereupon, and the photosensitive polymericlayer disposed on the photosensitive polymeric layer. In suchembodiments, the second polymeric layer can serve as a protecting layerof the electronic substrate when the electronic substrate is sensitiveto an organic developer (e.g., when the electronic substrate is anorganic substrate). In such embodiments, after development, part of thewater soluble second polymeric layer (i.e., that under theunexposed/developed portion of the photosensitive polymeric layer) canbe removed by using water, and the rest of second polymeric layer (i.e.,that under the exposed/undeveloped portion of the photosensitivepolymeric layer) can remain in the device thus formed.

The contents of all publications cited herein (e.g., patents, patentapplication publications, and articles) are hereby incorporated byreference in their entirety.

The disclosure will now be described in greater detail by reference tothe following non-limiting examples.

EXAMPLES Synthesis Example 1 (Poly-1)

The polymerization reaction was performed in a one liter three-neck,jacketed round bottomed flask equipped with a mechanical agitator, athermocouple and a nitrogen inlet to keep positive nitrogen pressurethroughout the reaction. The flask was charged with 101.9 grams ofbenzophenone-3,3′,4,4′-tetracarboxylic dianhydride (BTDA), 35.10 gramsof hexafluoroisopropylidenediphthalic anhydride (6FDA) and 178.0 gramsof anhydrous NMP. The contents were agitated at 18-20° C. 53.35 grams of1-(4-aminophenyl)-1,3,3-trimethylindan-5-amine (DAPI), and 30.20 gramsof 2,4-diamino-1,3,5-trimethylbenzene (DAM) were dissolved in 358 gramsof dry NMP in a bottle. The diamine solution was added to the flask bypump for 1 hour at room temperature. The mixture was warmed to 60° C.and agitated for 3 hours to produce a polyamic acid.

To endcap the polyamic acid formed above, 20.5 grams of3-acryloyloxy-2,2-bis[(acryloyloxy)methyl]propyl1,3-dioxo-1,3-dihydro-2-benzofuran-5-carboxylate (PETA) was charged tothe flask. The mixture was agitated at 60° C. for 3 hours to form anendcapped polyamic acid.

To perform the imidization reaction of the above endcapped polyamicacid, 50.0 grams of acetic anhydride and 20.0 grams of pyridine werecharged to the flask. The reaction mixture was warmed to 110° C. andagitated for 12 hours. A small sample (1 g) was withdrawn andprecipitated into 50:50 methanol:water (10 ml). The solid was isolatedby filtration and dried. FTIR analysis showed that the imidizationreaction was complete (showed absence of amide and anhydride peaks).

The solution was cooled to room temperature and added dropwise to 10liters of vigorously stirred de-ionized water to precipitate thepolymer. The polymer was collected by filtration and washed with 600grams of de-ionized water. The cake was re-slurried with four liters ofmethanol and filtered. The wet cake was dried in air for 12 hours andthen the polymer was dried under vacuum at 70° C. for 15 hours. Themolecular weight of the resultant polyimide polymer measured by GPC was32800 Daltons.

Composition Example 1 Formulation of a Polymer Solution for Preparationof Dry Film (F-1)

To a 3-neck round bottom flask equipped with a mechanical stirrer wasadded 500 parts of GBL, 85.2 parts of the polymer obtained in SynthesisExample 1, 6 parts of a 0.5% solution of PolyFox 6320 (available fromOMNOVA Solutions), 3 parts of (3-glycidyloxypropyl)trimethoxy silane, 3parts of NCI-831 (trade name, available from ADEKA corporation), 2 partsof diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide, 33.75 parts oftetraethylene diacrylate, 11.25 parts of pentaerylthritol triacrylateand 15.1 g of polyamic ester of Structure PAE-1. The above compositionwas mechanically stirred for 18 hours and was then filtered by using a1.0 μm filter (Ultradyne from Meissner Filtration Product, Inc., cat.no. CFTM11.0-44B1).

Dry Film Example DF-1

A filtered photosensitive solution of F-1 was applied via slot-diecoater from Frontier Industrial Technologies (Towanda, Pa.) with a linespeed of 10 feet/minutes (300 cm per minutes) onto a polyethyleneterephthalate (PET) film TA 30 (manufactured by Toray Plastics America,Inc.) having a thickness of 36 μm used as a carrier substrate and driedat 200° F. to obtain a photosensitive polymeric layer with a thicknessof approximately 4.0 microns. The speed of pump was 14 RPM. On thispolymeric layer, a biaxially oriented polypropylene (BOPP) film(manufactured by IMPEX GLOBAL LLC, trade name 80ga BOPP) was laid overby a roll compression to act as a protective layer.

Melt Viscosity Measurement of Dry Film DF-1

A Brookfield Viscometer Model CAP 2000+ H was used to measure the meltviscosity of the unbaked polymeric layer in the dry film DF-1 describedabove. This viscometer was designed to measure viscosity of samples attemperatures ranged from 50° C. to 235° C. The polymeric layer wasseparated from the protective layer and the carrier substrate, and wascut into small pieces. The amount of sample equivalent to about 40micro-liter was placed onto the center of the viscometer plate which wasset at 50° C. The spindle was lowered and the thermal equilibrium wasallowed to be reached. The viscosity of the samples and correspondingmelt temperatures are summarized in Table 1.

TABLE 1 Temperature, ° C. Viscosity, P 50 74.4 60 69.0 70 60.9 80 71.190 77.8 100 119.6

Lamination of Dry Film Example L-1

After the removal of the protective layer by peeling, the photosensitivepolymeric layer of dry film structure DF-1 (6″×6″) was placed on 4″Wafernet copper coated wafer). The polymeric layer was laminated onto Cucoated wafer by vacuum lamination (0.54-0.6 Torr) at 80° C. followed bybeing subjected to a pressure of 40 psi. Lamination process was done byusing a DPL-24A Differential Pressure Laminator manufactured by OPTEK,NJ.

Lithographic Evaluation of Laminated DF-1

The carrier substrate of the copper wafer laminated by composition DF-1in Example L-1 was removed. The photosensitive polymeric layer was thenexposed to actinic light utilizing an i-line stepper in a patternedexposure array, which incrementally increased exposure energy by 50mJ/cm² with a starting exposure energy of 50 mJ/cm². The exposed filmwas then heated at 50° C. for 3 minutes, and developed using two30-second puddles with a solution containing 70% GBL and 30%cyclopentanone. The film was then washed with PGMEA. A relief patternwith a resolution of 2 microns was obtained at energy dose of 100mJ/cm². The final film thickness was 3.6 μm and film thickness loss was10.0%.

Composition Example 2 Formulation of a Polymer Solution for Preparationof Dry Film (F-2)

Formulation F-2 was prepared in the same manner as F-1 except that theamount of GBL was reduced from 500 parts to 313.1 parts.

Dry Film Example DF-2

A filtered photosensitive solution of F-2 was applied via slot-diecoater from FujiFilm Manufacturing USA (Greenwood, S.C.) with a linespeed of 2.5 feet/minutes (75 cm per minutes) onto a polyethyleneterephthalate (PET) from Mitsubishi used as a carrier substrate anddried at 210° F. to obtain a photosensitive polymeric layer with athickness of approximately 2.1 microns. The speed of pump was 5 RPM. Onthis polymeric layer, a biaxially oriented polypropylene (BOPP) film(manufactured by IMPEX GLOBAL LLC, trade name 80ga BOPP) was laminatedby a roll compression to act as a protective layer.

Lamination of Dry Film Example L-2

After the removal of the protective layer by peeling, the photosensitivepolymeric layer of dry film structure DF-2 (6″×6″) was placed on a 4″Wafernet copper coated wafer). The polymeric layer was laminated ontothe Cu coated wafer by vacuum lamination (0.48-0.6 Torr) at 80° C. for90 seconds followed by being subjected to a pressure of 40 psi.Lamination process was done by using a DPL-24A Differential PressureLaminator manufactured by OPTEK, NJ.

Lithographic Evaluation of Laminated DF-2

The carrier substrate of the copper wafer laminated by composition DF-2in Example L-2 was removed. The photosensitive polymeric layer was thenexposed to actinic light utilizing an i-line stepper in a patternedexposure array, which incrementally increased exposure energy 50 mJ/cm²with a starting exposure energy of 50 mJ/cm². The exposed film was thenheated at 50° C. for 3 minutes, and developed using two 45-secondpuddles with a solution containing 70% GBL and 30% cyclopentanone. Thefilm was then washed with PGMEA. A relief pattern with a resolution of 2microns was obtained at energy dose of 100 mJ/cm². The final filmthickness was 1.92 μm and film thickness loss was 16.9%.

Synthesis Example 2 (P-2)

Solid 4,4′-(hexafluoroisopropylidene)bis(phthalic anhydride) (6FDA)(2.370 kg, 5.33 mole) was charged to a solution of1-(4-aminophenyl)-1,3,3-trimethylindan-5-amine (also known as4,4′-[1,4-phenylene-bis(1-methylethylidene)]bisaniline (DAPI)) (1.465kg, 5.51 mole) in NMP (9.86 kg) at 25° C. The reaction mixturetemperature was increased to 40° C. and allowed to react for 6 hours.Next, acetic anhydride (1.125 kg) and pyridine (0.219 kg) were added andthe reaction mixture temperature was increased to 100° C. and allowed toreact for 12 hours.

The reaction mixture above was cooled to room temperature andtransferred to a larger vessel equipped with a mechanical stirrer. Thereaction solution was diluted with ethyl acetate and washed with waterfor one hour. After the stirring was stopped, the mixture was allowed tostand undisturbed. Once phase separation had occurred, the aqueous phasewas removed. The organic phase was diluted with a combination of ethylacetate and acetone and washed twice with water. The amounts of organicsolvents (ethyl acetate and acetone) and water used in all of the washesare shown in Table 2.

TABLE 2 Wash 1 Wash 2 Wash 3 Ethyl Acetate (kg) 20.5 4.1 4.1 Acetone(kg) — 2.3 2.3 Water (kg) 22.0 26.0 26.0

GBL (10 kg) was added to the washed organic phase and the solution wasconcentrated by vacuum distillation to give a polymer solution P-1. Thesolid % of final polymer was 29.94% and the weight average molecularweight (Mw) measured by GPC was 51,000 Daltons.

To measure the molecular weight by GPC, 200 mg of the above polymersolution was first dissolved in 3.2 g of tetrahydrofuran (THF) thatincluded BHT. The instrument used was a Waters Gel PermeationChromatograph and the software was Waters Empower 2 Chromatographicsoftware (GPC module). The standard used was five polystyrene standardsand one p-cresol dimer standard. Their Mw values were as follows:198400, 89300, 19100, 4000, and 1200 for polystyrene standards and 228for p-cresol dimer. The column used was a Phenomenex Guard column:Phenogel-10, 7.8 mm ID×50 mm length and the flow rate was one milliliterper minute at 35° C.

Composition Example 3 Formulation of a Polymer Solution for Preparationof Dry Film (F-3)

A photosensitive composition was prepared by using 193.6 g of polymer(P-2), 43.0 g of GBL, 3.75 g of a 0.5 wt % solution of PolyFox 6320(available from OMNOVASolutions) in GBL, 3.15 g ofmethacryloxypropyltrimethoxysilane, 1.90 g of NCI-831 (trade name,available from ADEKA corporation), 0.15 g para-benzoquinone, 21.10 g oftetraethylene glycol diacrylate and 7.05 g of pentaerythritoltriacrylate. After being stirred mechanically for 24 hours, the solutionwas filtered using a 0.2 μm filter (Ultradyne from Meissner FiltrationProduct, Inc., cat. no. CFTM10.2-44B1).

Dry Film Example DF-3

The filtered photosensitive solution F-3 was applied using reversemicrobar coater from Fujifilm Manufacturing USA (Greenwood, S.C.) with aline speed of 2 feet/minutes (60 cm per minutes) with 30 um microbarclearance onto a polyethylene terephthalate (PET) film (TA 30,manufactured by Toray Plastics America, Inc.) having a width of 16.2″and thickness of 35 μm used as a carrier substrate and dried at 210° F.to obtain a photosensitive polymeric layer with a thickness ofapproximately 5.0 microns. On this polymeric layer, a biaxially orientedpolypropylene film having width of 18″ and thickness of 20 μm (BOPP,manufactured by Mirwec Film Inc, Bloomington, Ind., trade name BOPLON)was laid over by a roll compression to act as a protective layer.

Lamination of Dry Film Example L-3

After the removal of the protective layer by peeling, the photosensitivepolymeric layer of dry film structure DF-3 (6″×6″) was placed on a 4″Wafernet copper coated wafer. The polymeric layer was laminated onto theCu coated wafer by vacuum lamination (0.2-0.4Torr) at 90° C. for 90seconds followed by being subjected to a pressure of 40 psi (in thefirst 20 seconds only vacuum was applied, then in the next 90 secondsboth pressure and vacuum was applied). Lamination process was done byusing a DPL-24A Differential Pressure Laminator manufactured by OPTEK,NJ.

Lithographic Evaluation of Laminated DF-3

The carrier substrate of the copper wafer laminated by dry filmstructure DF-3 in Example L-3 was removed. The photosensitive polymericlayer was then exposed to actinic light utilizing an i-line stepper in apatterned exposure array, which incrementally increased exposure energyby 50 mJ/cm² with a starting exposure energy of 50 mJ/cm². The exposedfilm was then heated at 50° C. for 3 minutes, and developed using two75-second puddles using cyclopentanone. The film was then washed withPGMEA for 15 seconds. A relief pattern with a resolution of 2 micronswas obtained at energy dose of 100 mJ/cm². The film thickness loss was26.7%.

Synthesis Example 3 (Poly-3)

The procedure was the same as for Synthesis Example 1 except that theratio of dianhydrides to diamines was 0.95.

The work-up was similar to Synthesis Example 1. The molecular weight ofthe resultant polyimide polymer measured by GPC was 24,000 Daltons.

Composition Example 4 Formulation of a Polymer Solution for Preparationof Dry Film (F-4)

To a 3-neck round bottom flask equipped with a mechanical stirrer wasadded 550 parts of GBL, 100 parts of the polymer Poly-3 obtained inSynthesis Example 3, 3 parts of a 0.5% solution of PolyFox 6320(available from OMNOVA Solutions), 3 parts of(3-glycidyloxypropyl)trimethoxy silane, 3 parts of NCI-831 (trade name,available from ADEKA corporation), 33.75 parts of tetraethylenediacrylate, 11.25 parts of pentaerylthritol triacrylate and 0.2 parts ofp-benzoquinone. The above composition was mechanically stirred for 18hours and was then filtered by using a 0.2 μm filter (Ultradyne fromMeissner Filtration Product, Inc., cat. no. CFTM10.2-44B1).

Dry Film Example DF-4

Procedure was the same as that for DF-3 except a filtered photosensitivesolution of F-4 was used to obtain a photosensitive polymeric layer witha thickness of approximately 5.0 microns.

Lamination of Dry Film Example L4

Procedure was the same as for L3 except dry film DF-4 was used.

While the subject matter of this disclosure has been described in detailwith reference to certain embodiments thereof, it will be understoodthat modifications and variations are within the spirit and scope ofthat which is described and claimed.

What is claimed is:
 1. A dry film structure, comprising: a carriersubstrate; and a photosensitive polymeric layer supported by the carriersubstrate; the photosensitive polymeric layer comprises at least onefully imidized polyimide polymer; wherein the photosensitive polymericlayer has a film thickness of at most about 5 microns.
 2. A dry filmstructure of claim 1 wherein, the photosensitive polymeric layer furthercomprises at least one reactive functional compound; and at least onephotoinitiator.
 3. The dry film structure of claim 1, wherein the atleast one fully imidized polyimide polymer is prepared from at least onediamine, the at least one diamine comprising a compound selected fromthe group consisting of a diamine of Structure (Ia) and a diamine ofStructure (Ib),

in which each of R¹, R², R³, R⁴, R⁵, R¹¹, R¹², R¹³, and R¹⁴,independently, is H, a substituted or unsubstituted C₁-C₆ linear orbranched alkyl group, or a C₅-C₇ cycloalkyl group.
 4. The dry filmstructure of claim 3, wherein the at least one diamine is selected fromthe group consisting of 1-(4-aminophenyl)-1,3,3-trimethylindan-5-amine,1-(4-aminophenyl)-1,3,3-trimethyl-2H-inden-5-amine,1-(4-aminophenyl)-1,3,3-trimethyl-indan-5-amine,[1-(4-aminophenyl)-1,3,3-trimethyl-indan-5-yl]amine, and1-(4-aminophenyl)-2,3-dihydro-1,3,3-trimethyl-1H-inden-5-amine),5-amino-6-methyl-1-(3′-amino-4′-methylphenyl)-1,3,3-trimethylindan,4-amino-6-methyl-1-(3′-amino-4′-methylphenyl)-1,3,3-trimethylindan,5,7-diamino-1,1-dimethylindan, 4,7-diamino-1,1-dimethylindan,5,7-diamino-1,1,4-trimethylindan, 5,7-diamino-1,1,6-trimethylindan, and5,7-diamino-1,1-dimethyl-4-ethylindan.
 5. The dry film structure ofclaim 3, wherein the at least one diamine further comprises at least onediamine of Structure (II),

wherein R¹⁵, R¹⁶, R¹⁷ and R¹⁸, independently, is H, a substituted orunsubstituted C₁-C₆ linear or branched alkyl group, or C₅-C₇ cycloalkylgroup, provided that at least two of R¹⁵, R¹⁶, R¹⁷ and R¹⁸ are nothydrogen.
 6. The dry film structure of claim 5, wherein the at least onediamine of Structure (II) is selected from the group consisting of2,3,5,6-tetramethylphenylene-diamine,2,4-diamino-1,3,5-trimethylbenzene, 2,4-diamino-1,3,5-triethylbenzene,2,4-diamino-3,5-dimethyl-1-ethylbenzene,2,4-diamino-1,5-dimethyl-3-ethylbenzene2,4-diamino-1,3,5-triisopropylbenzene,2,3,5,6-tetraisopropyl-phenylenediamine, and2,4-diamino-1,3,5,6-tetramethylbenzene.
 7. The dry film structure ofclaim 1, wherein the at least one fully imidized polyimide polymer isprepared from at least one dianhydride, the at least one dianhydridecomprising a compound selected from the group consisting of3,3′,4,4′-benzophenone tetracarboxylic dianhydride,3,3′,4,4′-diphenylsulfone tetracarboxylic dianhydride,3,3′,4,4′-diphenyl ether tetracarboxylic dianhydride, 2,3,3′,4′-diphenylether tetracarboxylic dianhydride, and 2,2-[bis(3,4-dicarboxyphenyl)]hexafluoropropane dianhydride.
 8. The dry film structure of claim 1,wherein the at least one fully imidized polyimide polymer is preparedfrom at least one dianhydride, the at least one dianhydride comprising acompound selected from the group consisting of:


9. The dry film structure of claim 2, wherein the reactive functionalcompound comprises at least one functional group selected from the groupconsisting of a vinyl group, an allyl group, a vinyl ether group, apropenyl ether group, a (meth)acryloyl group, an a SiH group, and athiol group.
 10. The dry film structure of claim 9, wherein the reactivefunctional compounds is selected from the group consisting of1,6-hexanediol di(meth)acrylate, tetraethyleneglycol di(meth)acrylate,divinylbenzene, ethoxylated bisphenol-A-di(meth)acrylate, diethyleneglycol bis(allyl carbonate), trimethylolpropane tri(meth)acrylate,ditrimethylolpropane tetra(meth)acrylate, pentaerythritoltri(meth)acrylate, pentaerythritol tetra(meth)acrylate,dipentaerythritol penta-/hexa-(meth)acrylate, isocyanuratetri(meth)acrylate, bis(2-hydroxyethyl)-isocyanurate di(meth)acrylate,1,3-butanediol tri(meth)acrylate, 1,4-butanediol tri(meth)acrylate,methyl (meth)acrylate, butyl (meth)acrylate, cyclohexyl (meth)acrylate,benzyl(meth)acrylate, neopentyl glycol di(meth)acrylate, (meth)acrylatemodified-urea-formaldehyde resins, (meth)acrylate modifiedmelamine-formaldehyde resins and (meth)acrylate modified cellulose. 11.The dry film structure of claim 1, wherein the photosensitive polymericlayer further comprises at least one adhesion promoter.
 12. The dry filmstructure of claim 1, wherein the photosensitive polymeric layer furthercomprises at least one surfactant.
 13. The dry film structure of claim1, wherein the photosensitive polymeric layer further comprises at leastone plasticizer.
 14. The dry film structure of claim 1, wherein thephotosensitive polymeric layer further comprises at least one additionalpolymer different from the at least one polyimide polymer.
 15. The dryfilm structure of claim 1, wherein the photosensitive polymeric layerfurther comprises at least one nanoparticle.
 16. The dry film structureof claim 1, further comprising a protective layer, wherein the firstpolymeric layer is between the carrier substrate and the protectivelayer.
 17. The dry film structure of claim 1, further comprising asecond polymeric layer, wherein the second polymeric layer is betweenthe photosensitive polymeric layer and the carrier substrate or thesecond polymeric layer is between the photosensitive polymeric layer andthe protective layer.
 18. The dry film structure of claim 17, whereinthe second polymeric layer comprises a water soluble polymer.
 19. Thedry film structure of claim 18, wherein the water soluble polymer isselected from the group consisting of poly(vinyl alcohol), poly(vinylpyrrolidone), poly(acrylic acid) and the salts thereof, poly(methacrylicacid) and the salts thereof, poly(acrylamide) and the salts thereof,poly(methacrylamide) and the salts thereof, poly(N-isopropylacrylamide)and the salts thereof, poly (2-oxazoline), poly(ethylene oxide),poly(propylene oxide), hydroxyethyl cellulose, hydroxypropyl cellulose,starch, polysaccharides, dextran, cyclodextran, and partially hydrolyzedpolyvinyl acetate.
 20. The dry film structure of claim 1, wherein thephotosensitive polymeric layer further comprises at least one solvent.21. The dry film structure of claim 20, wherein the solvent is fromabout 0.5 wt % to about 20 wt % of total weight of the photosensitivepolymeric layer.
 22. The dry film structure of claim 1, wherein thephotosensitive polymeric layer has a film thickness of at most about 4microns.
 23. The dry film structure of claim 1, wherein thephotosensitive polymeric layer has a film thickness of at most about 3microns.
 24. The dry film structure of claim 1, wherein thephotosensitive polymeric layer is capable of forming a patterned layercomprising at least one element having a feature size of at most about 3microns after the photosensitive polymeric layer is exposed to actinicradiation and developed.
 25. A process for preparation of a dry filmstructure, comprising: (a) coating a carrier substrate with aphotosensitive polymeric composition to form a coated composition; (b)drying the coated composition to form a photosensitive polymeric layer;and (c) optionally applying a protective layer to the photosensitivepolymeric layer to form a dry film structure; wherein the photosensitivepolymeric layer has a film thickness of at most about 5 microns.
 26. Theprocess of claim 25, wherein the photosensitive polymeric compositioncomprises: at least one fully imidized polyimide polymer; at least onereactive functional compound; and at least one photoinitiator.
 27. Aprocess, comprising: applying the dry film structure of claim 1 onto anelectronic substrate to form a laminate, wherein the photosensitivepolymeric layer is between the electronic substrate and the carriersubstrate.
 28. The process of claim 27, further comprising exposing thephotosensitive polymeric layer in the laminate to actinic radiation. 29.The process of claim 28, further comprising removing the carriersubstrate before or after exposing the photosensitive polymeric layer.30. The process of claim 29, further comprising removing unexposedportions in the polymeric layer by using a developer to form a patternedlayer having a relief pattern.
 31. The process of claim 30, furthercomprising rinsing the relief pattern on the substrate with a solvent ora mixture of solvents.
 32. A process of forming a patterned film,comprising: (a) providing a dry film structure comprising: a carriersubstrate; a protective layer; and a photosensitive polymeric layerbetween the carrier substrate and the protective layer, wherein thephotosensitive polymeric layer has a film thickness of at most about 5microns; (b) removing the protective layer from the dry film structure;(c) applying the structure obtained in step (b) onto an electronicsubstrate to form a laminate, the laminate comprising the photosensitivepolymeric layer between the electronic substrate and the carriersubstrate; and (d) converting the photosensitive polymeric layer into apatterned layer, thereby forming a patterned film comprising thepatterned layer; wherein the patterned layer has a thickness of at mostabout 5 microns and comprises at least one element having a feature sizeof at most about 3 microns.
 33. The process of claim 32, wherein thephotosensitive polymeric film comprises: at least one fully imidizedpolyimide; at least one reactive functional compound; and at least onephotoinitiator.
 34. The process of claim 32, wherein the patterned layerhas a thickness of at most about 4 microns.
 35. The process of claim 32,wherein the patterned layer has a thickness of at most about 3 microns.36. A three dimensional object, comprising at least one patterned filmformed by the process of claim
 32. 37. The three dimensional object ofclaim 36, comprising patterned films in at least two stacks.
 38. Thethree dimensional object of claim 36, comprising patterned films in atleast three stacks.
 39. A semiconductor device, comprising the threedimensional object of claim
 36. 40. The semiconductor device of claim39, wherein the semiconductor device is an integrated circuit, a lightemitting diode, a solar cell, or a transistor.